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Scientists use and test hypotheses in the development and refinement of models and scenarios that collectively serve as tools in the development of a theory. One alternative use of the term comes from psychological research. This usage is closer to the everyday usage of the. Popular usage also confuses the ideas of scientific fact and a scientific theory, which we distinguish by example in the discussion below. A datum is an observation or measurement recorded for subsequent analysis. The observation or measurement may be of a natural system or of a designed and constructed experimental situation.
Observation here includes indirect observation, which uses inference from well-understood science, as well as direct sensory observations. Thus the assertion that a particular skeleton comes from an animal that lived during a particular geological period is based on acceptance of the body of knowledge that led to the widely accepted techniques used to date the bones, techniques that are themselves the products of prior scientific study. In the elementary and middle school classroom, observation usually involves fewer inferences. For example, students may begin by conducting unaided observations of natural phenomena and then progress to using simple measurement tools or instruments such as microscopes.
When a scientific claim is demonstrated to occur forever and always in any context, scientists will refer to the claim as a fact e.
Facts are best seen as evidence and claims of phenomena that come together to develop and refine or to challenge explanations. For example, the fact that earthquakes occur has been long known, but the explanation for the fact that earthquakes occur takes on a different meaning if one adopts plate tectonics as a theoretical framework. The fact that there are different types of earthquakes shallow and deep.
A century ago the atomic substructure of matter was a theory, which became better established as new evidence and inferences based on this evidence deepened the complexity and explanatory power of the theory. Today, atoms are an established component of matter due to the modern capability of imaging individual atoms in matter with such tools as scanning-tunneling microscopes.
This kind of progression from theoretical construct to observed property leads to some confusion in the minds of many people about the nature of theory and the distinctions among theory, evidence, claims, and facts. The history of science further reveals that theories progress from hypotheses or tentative ideas to core explanations.
Core explanatory theories are those that are firmly established through accumulation of a substantial body of supporting evidence and have no competitors e. For much of science, theories are broad conceptual frameworks that can be invalidated by contradictions with data but can never be wholly validated. To give a specific example: Repeated observations give the rate of acceleration in this event, both its global average and local variations from that average.
These theories describe but do not actually explain gravitation in the conventional sense of that word; they invoke no underlying mechanism due to substructure and subsystems. In this example, drawn from physics, the theories are expressed in mathematical form and their predictions are thus both precise and specific.
They lend themselves readily to computer modeling and simulation. In other areas of science, theories can take more linguistic forms and involve other types of models. A theory may or may not include a mechanism for the effects it describes and predicts. Another important feature of the example is that it challenges a common perception of scientific revolutions.
However, it did not invalidate all that had gone before; instead, it showed clearly both the limitations of the previous theory and the domain in which the previous theory is valid as an excellent close approximation, useful because it is much simpler both conceptually and mathematically than the full general theory of relativity. This is a key understanding: Such theories are tentative in domains in which they have not yet been tested, or in which only limited data are available, so that the tests are not yet conclusive but are far from tentative in the domains in which they have repeatedly been tested through their use in new scientific inquiries.
In everyday usage, an argument is an unpleasant situation in which two or more people have differing opinions and become heated in their discussion of this difference. Argumentation in science has a different and less combative or competitive role than either of these forms Kuhn, It is a mode of logical discourse whose goal is to tease out the relationship between ideas and the evidence—for example, to decide what a theory or hypothesis predicts for a given circumstance, or whether a proposed explanation is consistent or not with some new observation.
The goal of those engaged in scientific argumentation is a common one: Alternative points of view are valued as long as they contribute to this process within the accepted norms of science and logic, but not when they offer alternatives that are viewed as outside those norms. In the modern world, some knowledge of science is essential for everyone. It is the opinion of this committee that science should be as nonnegotiable a part of basic education as are language arts and mathematics.
It is important to teach science because of the following:. Science is a significant part of human culture and represents one of the pinnacles of human thinking capacity. It provides a laboratory of common experience for development of language, logic, and problem-solving skills in the classroom. A democracy demands that its citizens make personal and community decisions about issues in which scientific information plays a fundamental role, and they hence need a knowledge of science as well as an understanding of scientific methodology.
The nation is dependent on the technical and scientific abilities of its citizens for its economic competitiveness and national needs. The science curriculum in the elementary grades, like that for other subject areas, should be designed for all students to develop critical basic knowledge and basic skills, interests, and habits of mind that will lead to productive efforts to learn and understand the subject more deeply in later grades.
If this is done well, then all five of the reasons to teach science will be well served. It is not necessary in these grades to distinguish between those who will eventually become scientists and those who will chiefly use their knowledge of science in making personal and societal choices. A good elementary science program will provide the basis for either path in later life. The specific content of elementary school science has been outlined in multiple documents, including the National Science Education Standards,. Teachers are held accountable to particular state and local requirements.
It is not the role of this report to specify a list of content to be taught. However, it is important to note that what this report says about science learning always assumes that there is a strong basis of factual knowledge and conceptual development in the science curriculum, and that the goal of any methodology for teaching is to facilitate student learning and understanding of this content, as well as developing their skills in, and understanding of, the methods of scientific observation, experimentation, modeling, and analysis.
It is often said that children are natural scientists. Rather than attempting to resolve this debate, we simply acknowledge the fact that children bring to science class a natural curiosity and a set of ideas and conceptual frameworks that incorporate their experiences of the natural world and other information that they have learned. Since these experiences vary, children at a given age have a wide range in their skills, knowledge, and conceptual development.
A key question for instruction is thus how to adapt the instructional goals to the existing knowledge and skills of the learners, as well as how to choose instructional techniques that will be most effective. Each of the views of science articulated above highlights particular modes of thought that are essential to that view. These views are not mutually exclusive descriptions of science, but rather each stresses particular aspects. Since students need to progress in all aspects, it is useful for teachers to have a clear understanding of each of these components of scientific development, just as they need a clear understanding of the subject matter, the specific science content, that they are teaching.
It is also useful at times to focus instruction on development of specific skills, in balance with a focus on the learning of specific facts or the understanding of a particular conceptual framework. Thus, if one looks from the perspective of science as a process of reasoning about evidence, one sees that logical argumentation and problem-solving skills are important.
One also sees a range of practices, such as model building and data representation, that each in itself is a specific skill and thus needs to be incorporated and taught in science classrooms. It is thus clear that multiple strategies are needed, some focused primarily on key skills or specific knowledge, others on particular conceptual understanding, and yet others on metacognition. The issues of what children bring to school and of how teaching can build on it to foster robust science learning with this rich multiplicity of aspects are the core topics of this report. Understanding science is multifaceted.
Research has often treated aspects of scientific proficiency as discrete. However, current research indicates that proficiency in one aspect of science is closely related to proficiency in others e. Like strands of a rope, the strands of scientific proficiency are intertwined. However, for purposes of being clear about learning and learning outcomes, the committee discusses these four strands separately see Box for a summary. The strands of scientific proficiency lay out broad learning goals for students.
They address the knowledge and reasoning skills that students must eventually acquire to be considered fully proficient in science. They are also a means to that end: The strands are not independent or separable in the practice of science, nor in the teaching and learning of science. Rather, the strands of scientific proficiency are interwoven and, taken together, are viewed as science as. Know, use, and interpret scientific explanations of the natural world. This strand includes acquiring facts and the conceptual structures that incorporate those facts and using these ideas productively to understand many phenomena in the natural world.
This includes using those ideas to construct and refine explanations, arguments, or models of particular phenomena. Generate and evaluate scientific evidence and explanations. This strand encompasses the knowledge and skills needed to build and refine models based on evidence. This includes designing and analyzing empirical investigations and using empirical evidence to construct and defend arguments. Understand the nature and development of scientific knowledge. Scientific knowledge is a particular kind of knowledge with its own sources, justifications, and uncertainties.
Students who understand scientific knowledge recognize that predictions or explanations can be revised on the basis of seeing new evidence or developing a new model. Participate productively in scientific practices and discourse. Students who see science as valuable and interesting tend to be good learners and participants in science. They believe that steady effort in understanding science pays off—not that some people understand science and other people never will. To engage productively in science, however, students need to understand how to participate in scientific debates, adopt a critical stance, and be willing to ask questions.
These strands of scientific proficiency represent learning goals for students as well as providing a broad framework for curriculum design. Evidence to date indicates that in the process of achieving proficiency in science, the four strands are intertwined, so that advances in one strand support and advance those in another. The committee thinks, and emerging evidence suggests, the development of proficiency is best supported when classrooms provide learning opportunities that interweave all four strands together in instruction.
The science-as-practice perspective invokes the notion that learning science involves learning a system of interconnected ways of thinking in a social context to accomplish the goal of working with and understanding scientific ideas. This perspective stresses how conceptual understanding of natural systems is linked to the ability to develop explanations of phenomena and to carry out empirical investigations in order to develop or evaluate knowledge claims.
The framework offers a new perspective on what is learned when students learn science. First, the strands emphasize the idea of knowledge in use. The content of each strand described below is drawn from research and differs from many typical presentations of goals for science learning. For example, we include an emphasis on theory building and modeling, which is often missing in existing standards and curricular frameworks. And, the fourth strand is often completely overlooked, but research indicates it is a critical component of science learning, particularly for students from populations that are typically underrepresented in science.
These strands illustrate the importance of moving beyond a simple dichotomy of instruction in terms of science as content or science as process. That is, teaching content alone is not likely to lead to proficiency in science, nor is engaging in inquiry experiences devoid of meaningful science content. Rather, students across grades K-8 are more likely to advance in their understanding of science when classrooms provide learning opportunities that attend to all four strands.
Knowing, using, and interpreting scientific explanations encompasses learning the facts, concepts, principles, laws, theories, and models of science. Understanding science requires that an individual integrate a complex structure of many types of knowledge, including the ideas of science, relationships between ideas, reasons for these relationships, ways to use the ideas to explain and predict other natural phenomena, and ways to apply them to many events. Understanding natural systems requires knowledge of conceptually central ideas and facts integrated in well-structured knowledge systems, that is, facts.
This strand stresses acquiring facts, building organized and meaningful conceptual structures that incorporate these facts, and employing these conceptual structures during the interpretation, construction, and refinement of explanations, arguments, or models. Generating and evaluating scientific evidence and explanations encompasses the knowledge and skills used for building and refining models and explanations conceptual, computational, mechanistic , designing and analyzing empirical investigations and observations, and constructing and defending arguments with empirical evidence.
This strand also incorporates the social practices e. Hence, it includes a wide range of practices involved in designing and carrying out a scientific investigation, including asking questions, deciding what to measure, developing measures, collecting data from the measures, structuring the data, interpreting and evaluating the data, and using the empirical results to develop and refine arguments, models, and theories. It also includes an awareness that science entails the search for core explanatory constructs and connections between them.
More specifically, students must recognize that there may be multiple interpretations of the same phenomena.
They must understand that explanations are increasingly valuable as they account for the available evidence more completely, and as they generate new, productive research questions. Students should be able to step back from evidence or an explanation and consider whether another interpretation of a particular finding is plausible with respect to existing scientific evidence and other knowledge that they.
This entails embracing a point of view as possible and worthy of further investigation, but subject to careful scrutiny and consideration of alternative perspectives which may be deemed more valuable in the end. To understand science, one must use science and do so in a manner that reflects the values of scientific practice.
Participation is premised on a view that science and scientific knowledge are valuable and interesting, seeing oneself as an effective learner and participant in science, and the belief that steady effort in understanding science pays off. The educational environment in particular is an important influence on how students view themselves as science learners and whether they feel supported to participate fully in the scientific community of the classroom. Viewing the science classroom as a scientific community akin to communities in professional science is advantageous although K-8 students are clearly not engaged in professional science.
Science advances in large part through interactions among members of research communities as they test new ideas, solicit and provide feedback, articulate and evaluate emerging explanations, develop shared representations and models, and reach consensus. Likewise, participation in scientific practices in the classroom helps students advance their understanding of scientific argumentation and explanations; engage in the construction of scientific evidence, representations, and models; and reflect on how scientific knowledge is constructed.
To participate fully in the scientific practices in the classroom, students need to develop a shared understanding of the norms of participation in science. This includes social norms for constructing and presenting a scientific argument and engaging in scientific debates. It also includes habits of mind, such as adopting a critical stance, a willingness to ask questions and seek help, and developing a sense of appropriate trust and skepticism. Interconnections among the strands in the process of learning are supported by research, although the strength of the research evidence varies across the strands.
The cognitive research literatures support the value of teaching content in the context of the practices of science. There is also mounting evidence that knowledge of scientific explanations of the natural world is advanced through generating and evaluating scientific evidence. For example, instruction designed to engage students in model-based reasoning advances their conceptual understanding of natural phenomena see, for example, Brown and Clement, ; Lehrer et al. Evidence for links between Strands 3 and 4 and the other two strands is less robust, but emerging findings are compelling.
Motivation, which is an element of Strand 4, clearly plays an important role in learning see Chapter 7. Although we have teased apart aspects of understanding and learning to do science as four interrelated strands, we do not separate these as separate learning objectives in our treatment of the pedagogical literature. Indeed, there is evidence that while the strands can be assessed separately, students use them in concert when engaging in scientific tasks Gotwals and Songer, Therefore, we contend that to help children develop conceptual understanding of natural systems in any deep way requires engaging them in scientific practices that incorporate all four strands to help them to build and apply conceptual models, as well as to understand science as a disciplinary way of knowing.
An important theme throughout this report is the complex interplay among development, learning and instruction, and the implications for science education. The evidence base for this report draws from several, mostly independent bodies of research, each emerging from different research traditions that operate within different theoretical frameworks. These frameworks differ in the relative emphasis placed on development versus learning and instruction. Reconciling these visions of competence and understanding their implications for how to support science learning require careful consider-.
In other words, through maturation with age, children will achieve certain cognitive milestones naturally, with little direct intervention from adults. There are significant problems with this assumption. As we show in the chapters in Part II , the cognitive developmental literature simply does not support this assumption. The foundation of research undermining a broad stage-like conception of cognitive development goes back at least three decades e.
In fact, variability in scientific reasoning within any age group is large, sometimes broader than the differences that separate contiguous age bands. In self-directed experimentation tasks, there are always some adults whose performance looks no better than that of the average child Klahr, Fay, and Dunbar, ; Kuhn, Schauble, and Garcia-Mila, ; Kuhn et al. Indeed, many adults never seem to master the heuristics for generating and interpreting evidence. Moreover, education, context, and domain expertise seem to play a strong role in whether and when these heuristics are appropriately used Kuhn, Stage-like conceptualizations of development also ignore the critical role of support and guidance by knowledgeable adults and peers.
As noted in the National Research Council report How People Learn , children need assistance to learn; building on their early capacities requires catalysts and mediation. In the case of the science classroom, both teachers and peers can and must fill these critical roles.
The power of schooling is its potential to make available other people, including. Indeed, observational and historical studies of working scientists reaf-firm the promise of looking closely at the ways in which environments support learning. These studies demonstrate that theory development and reasoning in science are components of an ensemble of activity that includes networks of participants and institutions Latour, ; specialized ways of talking and writing Bazerman, ; development of representations that render phenomena accessible, visualizable, and transportable Gooding, ; Latour, ; and efforts to manage material contingency by making instruments, machines, and other contexts of observation such as experimental apparatus.
The alignment of instruments, measures, and theories is never entirely principled e. For example, the idea that prior to middle school children are incapable of designing controlled experiments has been a ubiquitous assumption in the elementary school science community. Indeed the Benchmarks for Scientific Literacy American Association for the Advancement of Science, included design of controlled experiments in their list of limitations of the scientific reasoning of third to fifth graders:. Research studies suggest that there are some limits on what to expect at this level of student intellectual development.
One limit is that the design of carefully controlled experiments is still beyond most students in middle grades. Indeed, instructional studies have documented success at teaching controlled experimental design to children in this grade span see Klahr and Nigam, ; Toth, Klahr, and Chen, As another example, consider the issue of reasoning about theory and evidence. The developmental literature related to this fundamental aspect of scientific reasoning is more complex, with some studies in support of the Benchmarks stance and some studies suggesting greater competence.
In Chapter 5 we discuss evidence related to both of these examples. Continuing with the examples used above, the differentiation of theory and evidence poses even more challenges. Furthermore, there is mounting evidence that instruction can advance these capabilities as well as many others. In short, young children have a broad repertoire of cognitive capacities directly related to many aspects of scientific practice, and it is problematic to view these as simply a product of cognitive development.
Rather, cognitive capacities directly related to scientific practice usually do not fully develop in and of themselves apart from instruction, even in older children or adults. These capacities need to be nurtured, sustained, and elaborated in supportive learning environments that provide effective scaffolding and targeted as important through assessment practices. Components of the cognitive system e. American Association for the Advancement of Science.
Benchmarks for science literacy. The development of evidence evaluation skills. Cognitive Development, 11, The genre and activity of the experimental article in science. University of Wisconsin Press. Journal of Experimental Child Psychology, 79, Child theories versus scientific theories: Differences in reasoning or differences in knowledge?
Applied and ecological perspectives pp. Domain-specific principles affect learning and transfer in children. Cognitive Science, 14 , Overcoming misconceptions by analogical reasoning: Abstract transfer versus explanatory model construction. Instructional Science, 18 , Situated cognition and the culture of learning. Educational Researcher, 18 1 , A study of thinking.
Conceptual change in childhood. Conceptual differences between children and adults. Mind and Language , 3 , Enrichment or conceptual change? Essays on biology and cognition pp. The role of central conceptual structures in the development of scientific and social thought. Cognitive, perceptuo-motor, and neurological perspectives pp.
All other things being equal: Acquisition and transfer of the control of variables strategy. Child Development, 70 5 , Conceptual change within and across ontological categories: Examples from learning and discovery in science. Minnesota studies in the philosophy of science pp. University of Minnesota Press. Categorization and representation of physics problems by experts and novices. Cognitive Science, 5, Knowing about guessing and guessing about knowing: Child Development, 67, Past, present, and future.
Rieser Ornstein, and C. The scientist as adult. Philosophy of Science, 63, University of Chicago Press. Experimentation and representation in the history of a theory. Studies on the natural sciences pp. In most children's minds, electricity begins at a source and goes to a target. This mental model can be seen in students' first attempts to light a bulb using a battery and wire by attaching one wire to a bulb.
Repeated activities will help students develop an idea of a circuit late in this grade range and begin to grasp the effect of more than one battery. Children cannot distinguish between heat and temperature at this age; therefore, investigating heat necessarily must focus on changes in temperature.
As children develop facility with language, their descriptions become richer and include more detail. Initially no tools need to be used, but children eventually learn that they can add to their descriptions by measuring objects—first with measuring devices they create and then by using conventional measuring instruments, such as rulers, balances, and thermometers.
By recording data and making graphs and charts, older children can search for patterns and order in their work and that of their peers. For example, they can determine the. As students get older, they can represent motion on simple grids and graphs and describe speed as the distance traveled in a given unit of time.
Fundamental concepts and principles that underlie this standard include. Objects have many observable properties, including size, weight, shape, color, temperature, and the ability to react with other substances. Those properties can be measured using tools, such as rulers, balances, and thermometers.
Objects are made of one or more materials, such as paper, wood, and metal. Objects can be described by the properties of the materials from which they are made, and those properties can be used to separate or sort a group of objects or materials. Materials can exist in different states—solid, liquid, and gas. Some common materials, such as water, can be changed from one state to another by heating or cooling. The position of an object can be described by locating it relative to another object or the background.
An object's motion can be described by tracing and measuring its position over time. The position and motion of objects can be changed by pushing or pulling. The size of the change is related to the strength of the push or pull. Sound is produced by vibrating objects. The pitch of the sound can be varied by changing the rate of vibration. Light travels in a straight line until it strikes an object. Light can be reflected by a mirror, refracted by a lens, or absorbed by the object. Heat can be produced in many ways, such as burning, rubbing, or mixing one substance with another.
Heat can move from one object to another by conduction. Electricity in circuits can produce light, heat, sound, and magnetic effects. Electrical circuits require a complete loop through which an electrical current can pass. As a result of activities in grades K-4, all students should develop understanding of. During the elementary grades, children build understanding of biological concepts through direct experience with living things, their life cycles, and their habitats. These experiences emerge from the sense of wonder.
How many different animals are there? Why do some animals eat other animals? What is the largest plant? Where did the dinosaurs go? Making sense of the way organisms live in their environments will develop some understanding of the diversity of life and how all living organisms depend on the living and nonliving environment for survival. Because the child's world at grades K-4 is closely associated with the home, school, and immediate environment, the study of organisms should include observations and interactions within the natural world of the child.
The experiences and activities in grades K-4 provide a concrete foundation for the progressive development in the later grades of major biological concepts, such as evolution, heredity, the cell, the biosphere, interdependence, the behavior of organisms, and matter and energy in living systems. Children's ideas about the characteristics of organisms develop from basic concepts of living and nonliving. Piaget noted, for instance, that young children give anthropomorphic explanations to organisms.
In lower elementary grades, many children associate "life" with any objects that are active in any way. This view of life develops into one in which movement becomes the defining characteristic. Eventually children incorporate other concepts, such as eating, breathing, and reproducing to define life.
As students have a variety of experiences with organisms, and subsequently develop a knowledge base in the life sciences, their anthropomorphic attributions should decline. In classroom activities such as classification, younger elementary students generally use mutually exclusive rather than hierarchical categories. Young children, for example, will use two groups, but older children will use several groups at the same time. Students do not consistently use classification schemes similar to those used by biologists until the upper elementary grades.
As students investigate the life cycles of organisms, teachers might observe that young children do not understand the continuity of life from, for example, seed to seedling or larvae to pupae to adult. But teachers will notice that by second grade, most students know that children resemble their parents. Students can also differentiate learned from inherited characteristics. However, students might hold some naive thoughts about inheritance, including the belief that traits are inherited from only one parent, that certain traits are inherited exclusively from one parent or the other, or that all traits are simply a blend of characteristics from each parent.
Young children think concretely about individual organisms. For example, animals are associated with pets or with animals kept in a zoo. The idea that organisms depend on their environment including other organisms in some cases is not well developed in young children. In grades K-4, the focus should be on establishing the primary association of organisms with their environments and the secondary ideas of dependence on. Lower elementary students can understand the food link between two organisms. Organisms have basic needs. For example, animals need air, water, and food; plants require air, water, nutrients, and light.
Organisms can survive only in environments in which their needs can be met. The world has many different environments, and distinct environments support the life of different types of organisms. Each plant or animal has different structures that serve different functions in growth, survival, and reproduction. For example, humans have distinct body structures for walking, holding, seeing, and talking. The behavior of individual organisms is influenced by internal cues such as hunger and by external cues such as a change in the environment. Humans and other organisms have senses that help them detect internal and external cues.
Plants and animals have life cycles that include being born, developing into adults, reproducing, and eventually dying. The details of this life cycle are different for different organisms. Many characteristics of an organism are inherited from the parents of the organism, but other characteristics result from an individual's interactions with the environment. Inherited characteristics include the color of flowers and the number of limbs of an animal.
Other features, such as the ability to ride a bicycle, are learned through interactions with the environment and cannot be passed on to the next generation. All animals depend on plants. Some animals eat plants for food. Other animals eat animals that eat the plants. An organism's patterns of behavior are related to the nature of that organism's environment, including the kinds and numbers of other organisms present, the availability of food and resources, and the physical characteristics of the environment.
When the environment changes, some plants and animals survive and reproduce, and others die or move to new locations. All organisms cause changes in the environment where they live. Some of these changes are detrimental to the organism or other organisms, whereas others are beneficial. Humans depend on their natural and constructed environments. Humans change environments in ways that can be either beneficial or detrimental for themselves and other organisms.
As a result of their activities in grades K-4, all students should develop an understanding of. Young children are naturally interested in everything they see around them—soil, rocks, streams, rain, snow, clouds, rainbows, sun, moon, and stars. During the first years of school, they should be encouraged to observe closely the objects and materials in their environment, note their properties, distinguish one from another and develop their own explanations of how things become the way they are.
As children become more familiar with their world, they can be guided to observe changes, including cyclic changes, such as night and day and the seasons; predictable trends, such as growth and decay, and less consistent changes, such as weather or the appearance of meteors. Children should have opportunities to observe rapid changes, such as the movement of water in a stream, as well as gradual changes, such as the erosion of soil and the change of the seasons.
Children come to school aware that earth's surface is composed of rocks, soils, water, and living organisms, but a closer look will help them identify many additional properties of earth materials. By carefully observing and describing the properties of many rocks, children will begin to see that some rocks are made of a single substance, but most are made of several substances.
In later grades, the substances can be identified as minerals. Understanding rocks and minerals should not be extended to the study of the source of the rocks, such as sedimentary, igneous, and metamorphic, because the origin of rocks and minerals has little meaning to young children. Playgrounds and nearby vacant lots and parks are convenient study sites to observe a variety of earth materials.
As students collect rocks and observe vegetation, they will become aware that soil varies from place to place in its color, texture, and reaction to water. By planting seeds in a variety of soil samples, they can compare the effect of different soils on plant growth. If they revisit study sites regularly, children will develop an understanding that earth's surface is constantly changing. They also can simulate some changes, such as erosion, in a small tray of soil or a stream table and compare their observations with photographs of similar, but larger scale, changes.
By observing the day and night sky regularly, children in grades K-4 will learn to identify sequences of changes and to look for patterns in these changes. As they observe changes, such as the movement of an object's shadow during the course of a day, and the positions of the sun and the moon, they will find the patterns in these movements.
They can draw the moon's shape for each evening on a calendar and then determine the pattern in the shapes over several weeks. These understandings should be confined to observations,. The students are to observe and record information about the daily weather. He focuses on the aspects of weather that his teaching experience and knowledge from research on student abilities lead him to believe are developmentally appropriate, and he keeps a record of terms to help him modify his plans as the activity progresses.
Students design instruments for measuring weather that are within the range of their skills and a parent provides expertise. They make measurements using their mathematical knowledge and skills; they organize data in a meaningful way and communicate the data to other students. There is an ebb and flow of teacher-directed, whole-class discussions and small-group work sessions. In planning for the weather station, Mr.
Because of their age, the students would not be studying the causes of weather change such as air pressure, the worldwide air currents, or the effects of land and sea masses.
Rather, over the course of the year, they would identify and observe the elements of weather; devise and use measurement and data collection strategies; build measurement instruments; analyze data to find patterns and relationships within the data; and communicate their work to the entire school.
After a discussion of students' experiences with and ideas about weather, Mr. The children quickly identified the need to record whether the day was sunny or cloudy, presence of precipitation, and the temperature. What kinds of clouds were evident? How much precipitation accumulated? How did temperature change during the day? What was the wind speed and direction? One student said that he had heard on the weather report that there was a high-pressure front moving in. What is a front, he asked, and is it important? At the end of the discussion, someone mentioned humidity and recalled the muggy heat wave of the summer.
He wondered about the last two items—humidity and air pressure. Those concepts were well beyond the students' ability to fully understand, yet they were familiar with the words. Groups worked in the classroom and in the library; each group chose one aspect of weather for its focus. He encouraged the groups to get together and compare notes.
Twice during the week, the whole class came together and groups shared their work while students critiqued and offered ideas.
Several weeks later, the weather station of the fourth grade was in operation. After much work, including some trial and error, library research, and the helpful input of a parent who was a skilled mechanic, the students were recording data twice a day for wind direction and speed, using a class-made anemometer and wind vane; temperature,. Design of the anemometer was extremely difficult. It was easy to build something that would turn in the wind, but the students needed help in figuring how to measure the speed.
The children were also measuring air pressure with a homemade barometer that a parent had helped one group construct. The interest of the student and her parent and the class' familiarity with the term seemed reason enough. The students recorded their data on charts in the classroom for 2 months. Then it was time to analyze the data, write the. Again, the work began with a discussion. What were some of the ideas that the students had about the weather after all this measuring and recording?
Were any patterns observed? Many students thought the temperature was getting lower; several noted that if it was windy one day, it rained the next day. As ideas were presented, other students agreed or challenged what was said. When the discussion quieted, he turned the students' attention to the list and asked them to think about which of the ideas on the board they might actually be able to confirm by reviewing the data. They listed several and agreed on the following list for a starting place: Is the temperature getting lower? What is the relationship between the direction of the wind and the weather the next day?
What happened when the pressure went down or up? Was it colder when it was cloudy? Several days later, the work was well under way. One group was working on a bar graph showing the total number of sunny, cloudy, and rainy days; another had made a temperature graph that showed the daily fluctuations and showed the weather definitely was getting colder; an interesting table illustrated that when the pressure dropped the weather usually seemed to get worse.
The next challenge was to prepare an interesting report for the school, highlighting all that had been learned. The weather class continued to operate the weather station all year. The students became quite independent and efficient in collecting data. The data were analyzed approximately every 2 months. Some new questions were considered, and the basic ones continued.
Not only did students learn to ask questions and collect, organize, and present data, they learned how to describe daily weather changes in terms of temperature, windspeed and direction, precipitation, and humidity. Attempting to extend this understanding into explanations using models will be limited by the inability of young children to understand that earth is approximately spherical.
They also have little understanding of gravity and usually have misconceptions about the properties of light that allow us to see objects such as the moon. Although children will say that they live on a ball, probing questions will reveal that their thinking may be very different. Students can discover patterns of weather changes during the year by keeping a journal. Younger students can draw a daily weather picture based on what they see out a window or at recess; older students can make simple charts and graphs from data they collect at a simple school weather station.
Emphasis in grades K-4 should be on developing observation and description skills and the explanations based on observations. Younger children should be encouraged to talk about and draw what they see and think. Older students can keep journals, use instruments, and record their observations and measurements. Earth materials are solid rocks and soils, water, and the gases of the atmosphere. The varied materials have different physical and chemical properties, which make them useful in different ways, for example, as building materials, as sources of fuel, or for growing the plants we use as food.
Earth materials provide many of the resources that humans use. Soils have properties of color and texture, capacity to retain water, and ability to support the growth of many kinds of plants, including those in our food supply. Fossils provide evidence about the plants and animals that lived long ago and the nature of the environment at that time.
The sun, moon, stars, clouds, birds, and airplanes all have properties, locations, and movements that can be observed and described. The sun provides the light and heat necessary to maintain the temperature of the earth. The surface of the earth changes. Some changes are due to slow processes, such as erosion and weathering, and some changes are due to rapid processes, such as landslides, volcanic eruptions, and earthquakes. Weather changes from day to day and over the seasons. Weather can be described by measurable quantities, such as temperature, wind direction and speed, and precipitation.
Objects in the sky have patterns of movement. The sun, for example, appears to move across the sky in the same way every day, but its path changes slowly over the seasons. The moon moves across the sky on a daily basis much like the sun. The observable shape of the moon changes from day to day in a cycle that lasts about a month.
The science and technology standards connect students to the designed world, offer them experience in making models of useful things, and introduce them to laws of nature through their understanding of how technological objects and systems work. This standard emphasizes developing the ability to design a solution to a problem and understanding the relationship of science and technology and the way people are involved in both.
This standard helps establish design as the technological parallel to inquiry in science. Like the science as inquiry standard, this standard begins the understanding of the design process, as well as the ability to solve simple design problems. Children in grades K-4 understand and can carry out design activities earlier than they can inquiry activities, but they cannot easily tell the difference between the two, nor is it important whether they can.
In grades K-4, children should have a variety of educational experiences that involve science and technology, sometimes in the same activity and other times separately. When the activities are informal and open, such as building a balance and comparing the weight of objects on it, it is difficult to separate inquiry from technological design. At other times, the distinction might be clear to adults but not to children. Children's abilities in technological problem solving can be developed by firsthand experience in tackling tasks with a technological purpose.
They also can study technological products and systems in their world—zippers, coat hooks, can openers, bridges, and automobiles. Children can engage in projects that are appropriately challenging for their developmental level—ones in which they must design a way to fasten, move, or communicate. They can study existing products to determine function and try to identify problems solved, materials used, and how well a product does what it is supposed to do.
An old technological device, such as an apple peeler, can be used as a mystery object for students to investigate and figure out what it does, how it helps people, and what problems it might solve and cause. Such activities provide excellent opportunities to direct attention to specific technology—the tools and instruments used in science. Suitable tasks for children at this age should have clearly defined purposes and be related with the other content standards.
Tasks should be conducted within immediately familiar contexts of the home and school. They should be straightforward; there should be only one or two well-defined ways to solve the problem, and there should be a single, well-defined criterion for success. Any construction of objects should. Titles in this example emphasize some important components of the assessment process. Superficially, this assessment task is a simple matching task, but the teacher's professional judgment is still key. For example, is the term "wind gauge" most appropriate or should the more technical term "anemometer" be used?
The teacher needs to decide if the use of either term places some students at a disadvantage. Teacher planning includes collecting pictures of weather instruments and ensuring that all students have equal opportunity to study them. A teacher who uses this assessment task recognizes that all assessments have strengths and weaknesses; this task is appropriate for one purpose, and other modes of assessment are appropriate for other purposes.
This assessment task presupposes that students have developed some understanding of weather, technology, changing patterns in the environment, and the roles science and technology have in society. The teacher examines the patterns in the responses to evaluate the individual student responses.
The K-4 content standard for earth science is supported by the fundamental concept that weather can be described in measurable quantities. Students match pictures of instruments used to measure weather conditions with the condition the instrument measures. Individual, short-answer responses to matching item format. When used in conjunction with other data, this assessment activity provides information to be used in assigning a grade. This assessment activity is appropriate at the end of a unit on the weather in grades 3 or 4. Match pictures of the following weather instruments with the weather condition they measure:.
Thermometers of various types, including liquid-expansion thermometers, metal-expansion thermometers and digital-electronic thermometers—used to measure temperature. Barometers of various types, including aneroid and mercury types—used to measure air pressure. Wind gauges of various sorts—instruments to measure windspeed or velocity. Student matches all instruments with their use. Student matches familiar forms of measuring instruments with their uses. A student might mistakenly say that the thermometer measures heat or might not understand the concepts of air pressure or humidity.
Students at this age cannot be expected to develop sophisticated understanding of the concepts of air pressure, humidity, heat, temperature, speed, or velocity. Over the course of grades K-4, student investigations and design problems should incorporate more than one material and several contexts in science and technology. A suitable collection of tasks might include making a device to shade eyes from the sun, making yogurt and discussing how it is made, comparing two types of string to see which is best for lifting different objects, exploring how small potted plants can be made to grow as quickly as possible, designing a simple system to hold two objects together, testing the strength of different materials, using simple tools, testing different designs, and constructing a simple structure.
It is important also to include design problems that require application of ideas, use of communications, and implementation of procedures—for instance, improving hall traffic at lunch and cleaning the classroom after scientific investigations. Experiences should be complemented by study of familiar and simple objects through which students can develop observation and analysis skills. By comparing one or two obvious properties, such as cost and strength of two types of adhesive tape, for example, students can develop the abilities to judge a product's worth against its ability to solve a problem.
During the K-4 years, an appropriate balance of products could come from the categories of clothing, food, and common domestic and school hardware.
Scientists and engineers often work in teams with different individuals doing different things that contribute to the results. The observation or measurement may be of a natural system or of a designed and constructed experimental situation. Complementary approaches and convergent findings. When all of the pendulums are hung on the peg board, the class is asked to interpret the results. In turn, the experiments and investigations students conduct become experiences that shape and modify their background knowledge.
A sequence of five stages—stating the problem, designing an approach, implementing a solution, evaluating the solution, and communicating the problem, design, and solution—provides a framework for planning and for specifying learning outcomes. However, not every activity will involve all of those stages, nor must any particular sequence of stages be followed.
For example, some activities might begin by identifying a need and progressing through the stages; other activities might involve only evaluating existing products. In problem identification, children should develop the ability to explain a problem in their own words and identify a specific task and solution related to the problem. Students should make proposals to build something or get something to work better; they should be able to describe and communicate their ideas.
Students should recognize that designing a solution might have constraints, such as cost, materials, time, space, or safety. Children should develop abilities to work individually and collaboratively and to use suitable tools, techniques, and quantitative measurements when appropriate.
Students should demonstrate the ability to balance simple constraints in problem solving. Students should evaluate their own results or solutions to problems, as well as those of. When possible, students should use measurements and include constraints and other criteria in their evaluations. They should modify designs based on the results of evaluations. Student abilities should include oral, written, and pictorial communication of the design process and product.
The communication might be show and tell, group discussions, short written reports, or pictures, depending on the students' abilities and the design project. People have always had questions about their world. Science is one way of answering questions and explaining the natural world. People have always had problems and invented tools and techniques ways of doing something to solve problems. Trying to determine the effects of solutions helps people avoid some new problems.
Scientists and engineers often work in teams with different individuals doing different things that contribute to the results. This understanding focuses primarily on teams working together and secondarily, on the combination of scientist and engineer teams. Women and men of all ages, backgrounds, and groups engage in a variety of scientific and technological work. Tools help scientists make better observations, measurements, and equipment for investigations. They help scientists see, measure, and do things that they could not otherwise see, measure, and do.
Some objects occur in nature; others have been designed and made by people to solve human problems and enhance the quality of life. Students in elementary school should have a variety of experiences that provide initial understandings for various science-related personal and societal challenges. Central ideas related to health, populations, resources, and environments provide the foundations for students' eventual understandings. Although the emphasis in grades K-4 should be on initial understandings, students can engage in some personal actions in local challenges related to science and technology.
Teachers should be aware of the concepts that elementary school students have about health. Most children use the word ''germs" for all microbes; they do not generally use the words "virus" or "bacteria," and when they do, they do not understand the difference between the two. Children generally attribute all illnesses to germs without distinction between contagious and noncontagious diseases and without understanding of organic, functional, or dietary diseases. Teachers can expect students to exhibit little understanding of ideas, such as different origins of disease, resistance to infection, and prevention and cure of disease.
Children link eating with growth, health, strength, and energy, but they do not understand these ideas in detail. They understand connections between diet and health and that some foods are nutritionally better than others, but they do not necessarily know the reasons for these conclusions. By grades 3 and 4, students regard pollution as something sensed by people and know that it might have bad effects on people and animals.
Children at this age usually do not consider harm to plants as part of environmental problems; however, recent media attention might have increased students awareness of the importance of trees in the environment. In most cases, students recognize pollution as an environmental issue, scarcity as a resource issue, and crowded classrooms or schools as population problems. Most young students conceive of these problems as isolated issues that can be solved by dealing with them individually.
For example, pollution can be solved by cleaning up the environment and producing less waste, scarcity can be solved by using less, and. Central ideas related to health, populations, resources, and environments provide the foundations for students' eventual understandings and actions as citizens. However, understanding the interrelationships is not the priority in elementary school. As students expand their conceptual horizons across grades K, they will eventually develop a view that is not centered exclusively on humans and begin to recognize that individual actions accumulate into societal actions.
Eventually, students must recognize that society cannot afford to deal only with symptoms: The causes of the problems must be the focus of personal and societal actions. Safety and security are basic needs of humans. Safety involves freedom from danger, risk, or injury.
Security involves feelings of confidence and lack of anxiety and fear. Student understandings include following safety rules for home and school, preventing abuse and neglect, avoiding injury, knowing whom to ask for help, and when and how to say no. Individuals have some responsibility for their own health. Students should engage in personal care—dental hygiene, cleanliness, and exercise—that will maintain and improve health. Understandings include how communicable diseases, such as colds, are transmitted and some of the body's defense mechanisms that prevent or overcome illness.
Nutrition is essential to health. Students should understand how the body uses food and how various foods contribute to health. Recommendations for good nutrition include eating a variety of foods, eating less sugar, and eating less fat. Different substances can damage the body and how it functions. Such substances include tobacco, alcohol, over-the-counter medicines, and illicit drugs. Students should understand that some substances, such as prescription drugs, can be beneficial, but that any substance can be harmful if used inappropriately.
Human populations include groups of individuals living in a particular location. One important characteristic of a human population is the population density—the number of individuals of a particular population that lives in a given amount of space. The size of a human population can increase or decrease. Populations will increase unless other factors such as disease or famine decrease the population. Resources are things that we get from the living and nonliving environment to meet the needs and wants of a population.
Some resources are basic materials, such as air, water, and soil; some are produced from basic resources, such as food, fuel, and building materials; and some resources are nonmaterial, such as quiet places, beauty, security, and safety. The supply of many resources is limited. If used, resources can be extended through recycling and decreased use. Environments are the space, conditions, and factors that affect an individual's and a population's ability to survive and their quality of life.
Changes in environments can be natural or influenced by humans. Some changes are good, some are bad, and some are neither good nor bad. Pollution is a change in the environment that can influence the health, survival, or activities of organisms, including humans. Some environmental changes occur slowly, and others occur rapidly. Students should understand the different consequences of changing environments in small increments over long periods as compared with changing environments in large increments over short periods. People continue inventing new ways of doing things, solving problems, and getting work done.
New ideas and inventions often affect other people; sometimes the effects are good and sometimes they are bad. It is helpful to try to determine in advance how ideas and inventions will affect other people. Science and technology have greatly improved food quality and quantity, transportation, health, sanitation, and communication. These benefits of science and technology are not available to all of the people in the world. Beginning in grades K-4, teachers should build on students' natural inclinations to ask questions and investigate their world.
Groups of students can conduct investigations that begin with a question and progress toward communicating an answer to the question. For students in the early grades, teachers should emphasize the experiences of investigating and thinking about explanations and not overemphasize memorization of scientific terms and information. Students can learn some things about scientific inquiry and significant people from history, which will provide a foundation for the development of sophisticated ideas related to the history and nature of science that will be developed in later years.
Through the use of short stories, films, videos, and other examples, elementary teachers can introduce interesting historical examples of women and men including minorities and people with disabilities who have made contributions to science. The stories can highlight how these scientists worked—that is, the questions, procedures, and contributions of diverse individuals to science and technology. In upper elementary grades, students can read and share stories that express the theme of this standard—science is a human endeavor.
Men and women have made a variety of contributions throughout the history of science and technology. Although men and women using scientific inquiry have learned much about the objects, events, and phenomena in nature, much more remains to be understood. Science will never be finished. Many people choose science as a career and devote their entire lives to studying it. Many people derive great pleasure from doing science. As a result of activities in grades , all students should develop. Students in grades should be provided opportunities to engage in full and in partial inquiries.
In a full inquiry students begin with a question, design an investigation, gather evidence, formulate an answer to the original question, and communicate the investigative process and results. In partial inquiries, they develop abilities and understanding of selected aspects of the inquiry process. Students might, for instance, describe how they would design an investigation, develop explanations based on scientific information and evidence provided through a classroom activity, or recognize and analyze several alternative explanations for a natural phenomenon presented in a teacher-led demonstration.
Students in grades can begin to recognize the relationship between explanation and evidence. They can understand that background knowledge and theories guide the design of investigations, the types of observations made, and the interpretations of data. In turn, the experiments and investigations students conduct become experiences that shape and modify their background knowledge.
With an appropriate curriculum and adequate instruction, middle-school students can develop the skills of investigation and the understanding that scientific inquiry is guided by knowledge, observations, ideas, and questions. Middle-school students might have trouble identifying variables and controlling more than one variable in an experiment. Students also might have difficulties understanding the influence of different variables in an experiment—for.
Teachers of science for middle-school students should note that students tend to center on evidence that confirms their current beliefs and concepts i. It is important for teachers of science to challenge current beliefs and concepts and provide scientific explanations as alternatives. Several factors of this standard should be highlighted.
The instructional activities of a scientific inquiry should engage students in identifying and shaping an understanding of the question under inquiry. Students should know what the question is asking, what. The students' questions should be relevant and meaningful for them. To help focus investigations, students should frame questions, such as "What do we want to find out about …? The instructional activities of a scientific inquiry should involve students in establishing and refining the methods, materials, and data they will collect. As students conduct investigations and make observations, they should consider questions such as "What data will answer the question?
In middle schools, students produce oral or written reports that present the results of their inquiries. Such reports and discussions should be a frequent occurrence in science programs. Students' discussions should center on questions, such as "How should we organize the data to present the clearest answer to our question?
The language and practices evident in the classroom are an important element of doing inquiries. Students need opportunities to present their abilities and understanding and to use the knowledge and language of science to communicate scientific explanations and ideas.
Writing, labeling drawings, completing concept maps, developing spreadsheets, and designing computer graphics should be a part of the science education. These should be presented in a way that allows students to receive constructive feedback on the quality of thought and expression and the accuracy of scientific explanations. This standard should not be interpreted as advocating a "scientific method. This standard cannot be met by having the students memorize the abilities and understandings. It can be met only when students frequently engage in active inquiries.
Students should develop the ability to refine and refocus broad and ill-defined questions. An important aspect of this ability consists of students' ability to clarify questions and inquiries and direct them toward objects and phenomena that can be described, explained, or predicted by scientific investigations.
Students should develop the ability to identify their questions with scientific ideas, concepts, and quantitative relationships that guide investigation. Students should develop general abilities, such as systematic observation, making accurate measurements, and identifying and controlling variables. They should also develop the ability to clarify their ideas that are influencing and guiding the inquiry, and to understand how those ideas compare with current scientific knowledge.
Students can learn to formulate questions, design investigations, execute investigations, interpret data, use evidence to generate explanations, propose alternative explanations, and critique explanations and procedures. The use of tools and techniques, including mathematics, will be guided by the question asked and the investigations students design.
The use of computers for the collection, summary, and display of evidence is part of this standard. Students should be able to access, gather, store, retrieve, and organize data, using hardware and software designed for these purposes. Students should base their explanation on what they observed, and as they develop cognitive skills, they should be able to differentiate explanation from description—providing causes for effects and establishing relationships based on evidence and logical argument. This standard requires a subject matter knowledge base so the students can effectively conduct investigations, because developing explanations establishes connections between the content of science and the contexts within which students develop new knowledge.
Thinking critically about evidence includes deciding what evidence should be used and accounting for anomalous data. Specifically, students should be able to review data from a simple experiment, summarize the data, and form a logical argument about the cause-and-effect relationships in the experiment. She wants students to develop an understanding of variables in inquiry and how and why to change one variable at a time. This inquiry process skill is imparted in the context of physical science subject matter.
The activity is purposeful, planned, and requires teacher guidance. Students keep records of the science activities, and Ms. The students in Ms. One experiment in this study is designed to enable the students to understand how and why to change one variable at a time. One student—the materials manager—goes to the supply table to pick up a length of string, scissors, tape, and washers of various sizes and weights.
Each group is directed to use these materials to 1 construct a pendulum, 2 hang the pendulum so that it swings freely from a pencil taped to the surface of the desk, and 3 count the number of swings of the pendulum in 15 seconds. The notetaker in each group records the result in a class chart. Because the number of swings recorded by each group is different, a lively discussion begins about why this happened. The students decide to repeat the experiment to make sure that they have measured the time and counted the swings correctly. When the second set of. Again the class discusses why the results are different.
Some of the suggestions include the length of the string, the weight of the washer, the diameter of the washer, and how high the student starting the pendulum held the washer to begin the swing. As each suggestion is made, Ms. The class is then asked to design experiments that could determine which suggestion is correct.
Each group chooses to do an experiment to test one of the suggestions, but before the group work continues, Ms. As the groups resume work, one group keeps the string the same length but attaches washers of different diameters and tries to start the swing at exactly the same place. Another group uses one piece of string and one washer, but starts the swing at higher and higher places on an arc.
A third group cuts pieces of string of different lengths, but uses one washer and starts the swing at the same place each time. Discussion is animated as students set up their pendulums and the class quiets as they count the swings. Finally, each group shares with the rest of the class what they did and the data they collected. The class concludes that the difference in the number of swings that the pendulum makes is due to the different lengths of string. The next day, students notice that Ms. Across the top are pegs from which to hang pendulums, and across the bottom are consecutive numbers.
The notetaker from each group is directed to hang the group's original pendulum on the peg corresponding to its number of swings in a fixed time. When all of the pendulums are hung on the peg board, the class is asked to interpret the results. After considerable discussion, the students conclude that the number of swings in a fixed time increases in a regular manner as the length of the string gets shorter.
After much measuring and counting and measuring again, and serious discussion on what counts as a "swing," every group declares success. Most students draw the pegboard with the pendulums of different lengths, but some students draw charts and a few make graphs. The next science class is spent discussing graphing as students move from their pictures of the string lengths, to lines, to points on a graph, and to a complete graph.
Finally, each student is asked to use his or her graph to make a pendulum that will swing an exact number of times. Students have described, explained, and predicted a natural phenomenon and learned about position and motion and about gathering, analyzing, and presenting data. Students should begin to state some explanations in terms of the relationship between two or more variables.
Students should develop the ability to listen to and respect the explanations proposed by other students. They should remain open to and acknowledge different ideas and explanations, be able to accept the skepticism of others, and consider alternative explanations. With practice, students should become competent at communicating experimental methods, following instructions, describing observations, summarizing the results of other groups, and telling other students about investigations and explanations.
Mathematics is essential to asking and answering questions about the natural world. Mathematics can be used to ask questions; to gather, organize, and present data; and to structure convincing explanations. Different kinds of questions suggest different kinds of scientific investigations.
Some investigations involve observing and describing objects, organisms, or events; some involve collecting specimens; some involve experiments; some involve seeking more information; some involve discovery of new objects and phenomena; and some involve making models. Current scientific knowledge and understanding guide scientific investigations.
Different scientific domains employ different methods, core theories, and standards to advance scientific knowledge and understanding. Technology used to gather data enhances accuracy and allows scientists to analyze and quantify results of investigations. Scientific explanations emphasize evidence, have logically consistent arguments, and use scientific principles, models, and theories.
The scientific community accepts and uses such explanations until displaced by better scientific ones. When such displacement occurs, science advances. Science advances through legitimate skepticism. Asking questions and querying other scientists' explanations is part of scientific inquiry. Scientists evaluate the explanations proposed by other scientists by examining evidence, comparing evidence, identifying faulty reasoning, pointing out statements that go beyond the evidence, and suggesting alternative explanations for the same observations.
Scientific investigations sometimes result in new ideas and phenomena for study, generate new methods or procedures for an investigation, or develop new technologies to improve the collection of data. All of these results can lead to new investigations. As a result of their activities in grades 5—8, all students should develop an understanding of. In grades 5—8, the focus on student understanding shifts from properties of objects and materials to the characteristic properties of the substances from which the materials are made.
In the K-4 years, students learned that objects and materials can be sorted and ordered in terms of their properties. During that process, they learned that some properties, such as size, weight, and shape, can be assigned only to the object while other properties, such as color, texture, and hardness, describe the materials from which objects are made. In grades , students observe and measure characteristic properties, such as boiling points, melting points, solubility, and simple chemical changes of pure substances and use those properties to distinguish and separate one substance from another.
Students usually bring some vocabulary and primitive notions of atomicity to the science class but often lack understanding of the evidence and the logical arguments that support the particulate model of matter. Their early ideas are that the particles have the same properties as the parent material; that is, they are a tiny piece of the substance. It can be tempting to introduce atoms and molecules or improve students' understanding of them so that particles can be used as an explanation for the properties of elements and compounds.
However, use of such terminology is premature for these stu. At this level, elements and compounds can be defined operationally from their chemical characteristics, but few students can comprehend the idea of atomic and molecular particles. The study of motions and the forces causing motion provide concrete experiences on which a more comprehensive understanding of force can be based in grades By using simple objects, such as rolling balls and mechanical toys, students can move from qualitative to quantitative descriptions of moving objects and begin to describe the forces acting on the objects.
Students' everyday experience is that friction causes all moving objects to slow down and stop. Through experiences in which friction is. In this example, Mr. B makes his plans using his knowledge and understanding of science, students, teaching, and the district science program. His understanding and ability are the results of years of studying and reflection on his own teaching.
He usually introduces new topics with a demonstration to catch the students' attention. He asks questions that encourage students to develop understanding and designs activities that require students to confirm their ideas and extend them to situations within and beyond the science classroom.
B encourages students to observe, test, discuss, and write by promoting individual effort as well as by forming different-sized groups of students for various activities. Immense understanding, skill, creativity, and energy are required to organize and orchestrate ideas, students, materials, and events the way Mr.
He wanted students to consolidate their experiences and think about the properties of substances as a foundation for the atomic theories they would gradually come to understand in high school. He knew that the students had some vocabulary and some notions of atomicity but were likely not to have any understanding of the evidence of the particulate nature of matter or arguments that support that understanding. As he had done the year before, he began the study with the density of liquids.
He knew that the students who had been in the district elementary schools had already done some work with liquids and that all students brought experience and knowledge from their daily lives. To clarify the knowledge, understanding, and confusion students might have, Mr. For the first day, he prepared two density columns: As the students arrived, they were directed into two groups to examine the columns and discuss what they saw.
After 10 minutes of conversation, Mr. When the writing ceased, Mr.