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AAAS  :: Project 2061  :: Textbook Evaluations

Middle Grades Science Textbooks: A Benchmarks-Based Evaluation

Science Insights. Addison-Wesley Publishing Company, 1996 and 1997
Earth Science Life Science Physical Science

About this Evaluation Report
Content Analysis
Instructional Analysis
I. [Explanation] This category consists of criteria for determining whether the curriculum material attempts to make its purposes explicit and meaningful to students, either in the student text itself or through suggestions to the teacher. The sequence of lessons or activities is also important in accomplishing the stated purpose, since ideas often build on each other.
II. [Explanation] Fostering understanding in students requires taking time to attend to the ideas they already have, both ideas that are incorrect and ideas that can serve as a foundation for subsequent learning. This category consists of criteria for determining whether the curriculum material contains specific suggestions for identifying and addressing students’ ideas.
III. [Explanation] Much of the point of science is to explain phenomena in terms of a small number of principles or ideas. For students to appreciate this explanatory power, they need to have a sense of the range of phenomena that science can explain. The criteria in this category examine whether the curriculum material relates important scientific ideas to a range of relevant phenomena and provides either firsthand experiences with the phenomena or a vicarious sense of phenomena that are not presented firsthand.
IV. [Explanation] Science literacy requires that students understand the link between scientific ideas and the phenomena that they can explain. Furthermore, students should see the ideas as useful and become skillful at applying them. This category consists of criteria for determining whether the curriculum material expresses and develops the key ideas in ways that are accessible and intelligible to students, and that demonstrate the usefulness of the key ideas and provide practice in varied contexts.
V. [Explanation] Engaging students in experiences with phenomena (category III) and presenting them with scientific ideas (category IV) will not lead to effective learning unless students are given time, opportunities, and guidance to make sense of the experiences and ideas. This category consists of criteria for determining whether the curriculum material provides students with opportunities to express, think about, and reshape their ideas, as well as guidance on developing an understanding of what they experience.
VI. [Explanation] This category consists of criteria for evaluating whether the curriculum material includes a variety of aligned assessments that apply the key ideas taught in the material.
VII. [Explanation] The criteria in this category provide analysts with the opportunity to comment on features that enhance the use and implementation of the curriculum material by all students.

I. Providing a Sense of Purpose

Conveying unit purpose (Rating = Poor)

Both units and chapters begin with a photograph and questions about it. No purpose is stated for the units, nor is any link made between the photograph and what will be studied in the unit. Each chapter photograph is accompanied by a statement of purpose in the student text (for example, “As you read this chapter, you will learn more about the origins of plants and their life processes” [p. 236s], and “As you read this chapter, you will learn how organisms interact with each other and their environment” [p. 536s]). Such purposes are not likely to have much meaning or be interesting to students who have had no prior experiences with the relevant phenomena. Overall, neither the introduction nor the subsequent material provides such phenomena. Students are not given the opportunity to think about the purpose and come up with their own phenomena. Given such a general chapter purpose, most lessons are consistent with it, but the purpose is not reverted to at the end of the chapter.

Conveying lesson/activity purpose (Rating = Poor)

The sections within chapters follow a typical pattern. They each start with a list of objectives that state what students will do, but not why. For example, on page 542s, the objectives are: “Identify the producers and consumers in an ecosystem,” “Distinguish between a food chain and a food web,” “Interpret an energy pyramid,” and “Make a model of a food chain.” Teachers are instructed to use the Skills WarmUp, which includes a modest statement of purpose in the Teacher’s Edition (e.g., “To help students understand plant chemistry” [p. 243t], “To help students understand the digestive process” [p. 415t], and “To help students think about which foods are nutritious” [p. 487t)], but they are not instructed to convey this purpose to students. Neither the text nor the activities in the sections convey a purpose.

Justifying lesson/activity sequence (Rating = Poor)

The chapters are sequenced to start from chemistry and biomolecules, move to cells and genetics, then to organs and systems, and finally to ecosystems. This approach may be logical to those who understand chemistry and see it as a foundation for the study of living things. However, for middle grades students (who have no knowledge of chemistry or its importance for understanding living things), there is no logic to the sequence.

Within chapters, there is no obvious logic to the order of the topics. For example, chapter 12 appears to be a collection of topics about plants rather than a strategic sequence. The topics are plant characteristics, plant evolution and classification, adaptations of flowering plants, hydroponics, photosynthesis, respiration, chemical interactions of plants, and science and society.

II. Taking Account of Student Ideas

Attending to prerequisite knowledge and skills (Rating = Poor)

The prerequisite ideas that are important for the treatment of the role of food in providing fuel and building material for humans (Idea a) are addressed. They include, for example, the idea that all matter is made up of atoms that can combine to form molecules (pp. 54–55s), and the idea that nutrients can be both organic and inorganic (pp. 64–65s). However, the prerequisites that are important for understanding the transformation of matter and energy in ecosystems are not addressed (Ideas c–e). That is, the idea that substances can combine with other substances to form new substances with new characteristics, so that substances can change form, but their elements are not created or destroyed, is not covered. Also, the idea that energy exists in many forms (particularly light and chemical energy) and can be changed from one form to another but cannot be created or destroyed—which is important for the subsequent lessons on energy pyramids (p. 545s)—is not covered. Teachers are not informed that these are prerequisites or told where they are treated. Furthermore, connections are not made to the prerequisites when they are needed.

Alerting teachers to commonly held student ideas (Rating = Poor)

Teachers are not alerted to the large body of published research on students’ misconceptions related to matter and energy transformations in ecosystems. Although each chapter includes a component labeled Misconceptions, it does not inform teachers about the findings of research studies on students’ misconceptions. Teachers are not advised about students’ commonly held ideas such as the idea that plants get their food from the environment (mainly from the soil), rather than manufacture it themselves, or that organisms and materials in the environment are very different types of matter and are not transformable into each other (Bell & Brook, 1984; Roth & Anderson, 1987; Anderson et al., 1990). And teachers are not cautioned that some students see ecosystems as only chains of events and processes in terms of creating and destroying matter rather than in terms of transforming matter from one substance to another (Smith & Anderson, 1986). In only one instance is a common student belief presented—the notion that “Students may think that photosynthesis takes place only in plant cells and respiration takes place only in animal cells” (p. 245t); this misconception is not explained sufficiently.

Assisting teachers in identifying their students’ ideas (Rating = Poor)

Although there is a component called Prior Knowledge, few of the questions in it are likely to help teachers identify their students’ ideas about the matter and energy transformations in organisms or the flow of matter and energy in ecosystems. For example, students are asked how they, other animals, and plants meet their energy needs (p. 542t), but this question is not likely to elicit students’ misconceptions about energy transformation. Similarly, a question, “Where do plants get nutrients?” is asked, but its objective is to probe what inorganic nutrients plants get from the soil (p. 243t). The purpose given for the former question about matter and energy is, “To gauge how much students know about how organisms in an ecosystem meet their energy needs,” but the question itself is not likely to be helpful (p. 542t). No questions ask students to make predictions or give explanations of phenomena, and teachers are not given suggestions of how to interpret students’ responses or probe their ideas further.

Addressing commonly held ideas (Rating = Poor)

Teachers are not given any support for addressing students’ misconceptions. In the only instance in which teachers are alerted to a misconception—the idea that students may think that “photosynthesis takes place only in plant cells and respiration takes place only in animal cells”—they are told to “Stress that both animal cells and plant cells use the process of respiration to release energy” (p. 245t). The one question that could focus students’ attention on the distinction between their own widely believed ideas and scientific ideas is included to evaluate them after their instruction has been completed; to wit, students are asked: “Sometimes it is said that plants use carbon dioxide to produce oxygen, while animals use oxygen to produce carbon dioxide. In what way is this statement misleading?” (p. 247s, Check and Explain, item 3).

III. Engaging Students with Relevant Phenomena

Providing variety of phenomena (Rating = Poor)

While Science Insights: Exploring Living Things addresses most of the key life science ideas, phenomena that can be explained by these ideas (and, hence, can serve to make the ideas plausible) are not included. Only the idea that plants use the energy from light to make “energy rich” sugars (Idea d1) is supported by a relevant phenomenon in the Science Insights series, but it is in the physical science textbook (Science Insights: Exploring Matter and Energy, p. 554s), rather than in the life science textbook. Students are told that sunlight consists of light of different wavelengths and that plants can absorb certain wavelengths better than others; then they are shown a graph of the rate of photosynthesis by wavelength. The life science textbook does include a few phenomena that could be used to support the ideas examined here, but it does not explain these phenomena in terms of the key ideas. For example, an activity in which students observe a color change after they blow into a jar containing cabbage-juice indicator (p. 248st) could support the idea that people break down sugars into simpler substances (Idea c3). However, while students are asked what substance in their breath made the color change (carbon dioxide), they are not asked to consider that the carbon dioxide was released from the breakdown of consumed sugars. No other phenomena were provided.

Providing vivid experiences (Rating = Poor)

The only experience described under the previous criterion that is relevant to the key ideas (namely, the change of color observed in cabbage-juice indicator) is not likely to provide students with a vicarious sense of the phenomenon. Furthermore, it is not likely to be comprehensible to them.

IV. Developing and Using Scientific Ideas

Introducing terms meaningfully (Rating = Poor)

Definitions of some terms are followed with examples, as is the case, for instance, for such terms as “producer,” “consumer,” “food chains,” and “food webs.” However, terms such as “photosynthesis” and “respiration” are not linked to experiences with phenomena. Although many of the excess terms found in other textbooks—for instance, “leaf parts” and “pigments”—are not used, yet other excess terms are used (e.g., “ATP,” “lipids,” “fermentation”), and some new ones are added (“lactic acid,” “glycogen,” “Calvin cycle”). In the end, the text uses 16 terms that go beyond the recommendations for middle grades found in Benchmarks for Science Literacy (American Association for the Advancement of Science, 1993) and National Science Education Standards (National Research Council, 1996).

Representing ideas effectively (Rating = Poor)

The representations in Science Insights: Exploring Living Things are not likely to make the abstract ideas about matter and energy transfer and transformation more intelligible to students. Furthermore, the representations are likely to be incomprehensible or confusing to them. The diagrams of photosynthesis (p. 98s) and the oxygen-carbon dioxide cycle (p. 245s) are not explained adequately. The photosynthesis diagram amounts to little more than text superimposed on a leaf diagram, and oxygen is not even indicated on the oxygen-carbon dioxide cycle. In several places, the equations for photosynthesis and respiration are presented in ways that could reinforce the common misconceptions that plants turn energy into matter. “Light Energy” is listed on the left side of the photosynthesis equation (p. 98s), and “Energy (ATP)” is listed on the right side of the respiration equation (pp. 99s, 245s). While the text mentions that during photosynthesis light energy is converted into chemical energy that is stored in sugar or starch (p. 98s), and the energy stored in glucose is released during respiration (p. 99s), students may remember only the equation (and this is what is asked of them in the chapter review (p. 108st, Check Your Knowledge, item 7). Although several representations are found in the Science Insights physical science textbook Exploring Matter and Energy (pp. 551–554s), too, they have similar problems.

Demonstrating use of knowledge (Rating = Poor)

No instances of modeling explanations or other uses of knowledge were found.

Providing practice (Rating = Poor)

The material provides a couple of questions, including novel questions, for only two of the key ideas; one question for two other ideas; and no questions for the rest of the ideas. For example, for the idea that food is both fuel and building material (Idea a), students are asked to (a) identify on a list of substances which ones contain carbon compounds and to explain their conclusions (p. 66st, Check and Explain, item 4), and (b) find out how many calories they use during a half hour of various activities (p. 69st, Make Connections, item 3). For the idea that plants produce sugar from carbon dioxide and water (Idea c1), the only question provided asks students: “What does a plant produce as the result of photosynthesis?” (p. 250st, Check Your Knowledge, item 5). Question sets do not increase in complexity, and there are no suggestions for teachers to provide feedback to students.

V. Promoting Students' Thinking about Phenomena, Experiences, and Knowledge

Encouraging students to explain their ideas (Rating = Poor)

No attempt is made to give students opportunities to express, clarify, or justify their ideas. Most of the questions (in components such as Skills WarmUp, Portfolio, Cooperative Learning, Discuss, Explore Visually, and Directed Inquiry) do not focus on the key life science ideas. The introduction to the Teacher’s Edition does not describe the purpose of these components or any other features of the program as intending to have students explain their own ideas.

Guiding student interpretation and reasoning (Rating = Poor)

While the Teacher’s Edition routinely contains in-text questions and discussion questions, these questions do not lead toward the key life science ideas. Frequently, they check for an understanding of simpler ideas (for example, to respond to a question about where they fit in the energy pyramid [p. 545s]), all that students need to know is what they and other similar organisms eat). Sometimes the questions focus on the key ideas, but the answers in the Teacher’s Edition do not. For example, students are asked how a terrarium is like the Earth’s biosphere (p. 545s), which could be used to address the idea that matter and energy are continual transferred in an ecosystem (Idea e). However, the answer provided is: “The terrarium provides everything the organisms in it need for survival.” In another example, a question asks, “What happens to the energy that comes to the plant from the outside?” which could be used for the idea that plants get energy by breaking down the sugars and releasing some of the energy as heat (Idea d2). But the answer provided is vague about how the energy is used by the plant: “It is trapped by the chlorophyll in green plant cells and then is used in the process of photosynthesis” (p. 98t). None of the questions have helpful characteristics. Questions from readings and activities do not frame important issues, anticipate student misconceptions, or help students to relate experiences to scientific ideas. The question sets (such as Explore Visually, and Check and Explain) are collections of questions rather than strategic sequences of questions that develop understanding of the key ideas.

Encouraging students to think about what they have learned (Rating = Poor)

No opportunities are suggested for students to revise their initial ideas or to monitor their progress in other ways.

VI. Assessing Progress

Aligning assessment to goals (Rating = Poor)

For the end-of-unit instruction assessment, Science Insights: Exploring Living Things provides two tests for each chapter and one test for each unit. They are presented in a separate Assessment Program booklet. The applicable components of chapters 12 and 25—the chapters that treat the key life science ideas most extensively—have been examined in terms of the first two assessment criteria.

Most of the key life science ideas are not assessed in Science Insights: Exploring Living Things, and for the key ideas that are assessed, an insufficient number of items is provided. Four true-or-false items focus on the key life science ideas. Two of them focus on the idea that decomposers transform dead materials into simpler, reusable substances (Idea c4), with students being asked whether or not “Consumers that feed only on the bodies of dead organisms are called decomposers” (Assessment Program, p. 126, Test 25A, item 20; the answer is yes), and “When decomposers break down the tissues of dead organisms, oxygen is released into the atmosphere” (p. 126, Test 25A, item 21; the answer is no).

Two other items focus on the idea that matter and energy are transferred from one organism to another (Idea e), with students being asked to provide the words that best complete the following statements: “In food _________, the flow of energy happens in one direction” (Assessment Program, p. 126, Test 25A, item 19; the answer is “chains”), and “Energy is lost at each stage of a food pyramid because ________ is used for life processes” (Assessment Program, p. 126, Test 25A, item 24; the answer is “energy”).

In addition, students are shown a diagram of a mature pine tree and a pine tree seedling and are asked to compare them and explain how the pine tree grew larger. They are to hypothesize about the materials and processes involved and to describe an experiment to test their hypothesis (Assessment Program, pp. 63–64, Test 12B, Part B, items 1–3).

Testing for understanding (Rating = Poor)

Of the relevant assessment items that are described in the previous criterion, only one task requires the application of a key idea—the task in which students explain the added mass of a pine tree. However, this is not typical.

Using assessment to inform instruction (Rating = Poor)

Science Insights: Exploring Living Things does not make explicit claims about assessment items that could be used to find out where students are and modify instruction accordingly. Nonetheless, the reviewers have examined whether questions throughout the relevant chapters could help a well-informed teacher to identify students’ remaining difficulties. Some relevant application questions were found in the Evaluate and Chapter Reviews sections of chapters 12 and 25. In chapter 12, students write a story from the point of view of a plant undergoing photosynthesis and explain “how a leaf makes and uses glucose” (p. 247st, Check and Explain, item 4); critique a statement that implies that only animals use oxygen (p. 247st, Check and Explain, item 3); predict and explain when they “expect a plant to take in more carbon dioxide, at night or during the day” (p. 250st, Check Your Understanding, item 5); and are asked in what form hydrogen is available to plants (p. 251st, Develop Your Skills, item 3b). In chapter 25, students explain how energy is lost at each level of a food web (p. 546st, Check and Explain, item 3), and why natural cycles are important to organisms (p. 552st, Check and Explain, item 2). Lastly, they design a fish tank and explain what natural cycles will take place in their fish tank (p. 558st, Check Your Understanding, item 3). Although, these questions require application of the key ideas, not all of the key life science ideas are assessed with such application questions (e.g., the idea that organisms break down sugars into simpler materials [Idea c3] is not assessed). Furthermore, no suggestions are given about how to probe beyond students’ initial responses.

VII. Enhancing the Science Learning Environment

Providing teacher content support (Minimal support is provided.)

The material provides minimal support in alerting teachers to how ideas have been simplified for students to comprehend and what the more sophisticated versions are. Content background notes only briefly summarize the student text for units (e.g., p. 72t, Unit Overview) and chapters (e.g., p. 236At, Overview; p. 486At, Overview).

The material rarely provides sufficiently detailed answers to questions in the Student Edition for teachers to understand and interpret various student responses. Most answers are brief and require further explanation (for example, “Accept all logical answers” [p. 558t, Check Your Understanding, item 8]); often, they emphasize factual recall of information from the student text (for example, “Photosynthesis requires light energy, carbon dioxide, and water” [p. 101t, Check and Explain, item 1]).

The material provides minimal support in recommending resources for improving teachers’ understanding of key ideas. While the material lists references at the beginning of each chapter that could help teachers improve their understanding of key ideas (e.g., “Pringle, Lawrence. Being a Plant. New York: Crowell, 1983” [p. 236Bt]), the lists lack annotations about what kind of information the references provide or how they may be helpful.

Encouraging curiosity and questioning (Minimal support is provided.)

The material provides no suggestions for how to encourage student questions and guide their search for answers.

The material provides a few suggestions for how to respect and value students’ ideas. Introductory teacher’s notes about concept mapping state that “each student connects concepts differently” and that working with other students in constructing concept maps “gives students valuable experience in comprehending and communicating the meanings of scientific concepts and terms” (p. T–35). In addition to concept mapping, the material explicitly elicits and values students’ ideas in some activities. For example, teacher’s notes state that answers may vary (e.g., p. 247t, Check and Explain, item 4) for selected tasks. Also, each chapter begins with a feature entitled, “What do you see?” which consists of a quote from an actual student about the chapter opening photograph (e.g., p. 486s).

The material provides a few suggestions for how to raise questions such as, “How do we know? What is the evidence?” and “Are there alternative explanations or other ways of solving the problem that could be better?” But it does not encourage students to pose such questions themselves. Specifically, the material includes a few tasks that ask students to provide evidence or reasons in their responses (e.g., p. 102st, Task 5 Conclusion; p. 248st, Task 5 Conclusion).

The material provides a few suggestions for how to avoid dogmatism. The first chapter portrays the nature of science as a durable yet dynamic human enterprise in which students can participate (pp. 2–11s). The material later illustrates changes over time in scientific thinking leading to the current system of plant classification (p. 241s, Historical Notebook). However, the material also contributes to dogmatism by presenting most of the text in a static, authoritative manner with little reference to the work of particular practicing scientists and by expecting single specific responses for most student tasks.

The material does not provide examples of classroom interactions (e.g., dialogue boxes, vignettes, or video clips) that illustrate appropriate ways for teachers to respond to student questions or ideas. However, a limited sense of desirable student-student interactions may be gained from procedural directions for laboratory and cooperative group activities (e.g., p. T–37; p. 248st, Activity 12; p. 247t, Cooperative Learning; Laboratory Manual, pp. T–x, T–xi).

Supporting all students (Some support is provided.)

The material generally avoids stereotypes or language that might be offensive to a particular group. For example, photographs include a diverse cultural mix of students and adults (e.g., pp. 14–15s, 247s, 496s), but the number of photographs that include people are few throughout the material. In addition, the material’s use of the short story genre (e.g., pp. 134–135st, 294–295st) related to the traditional expository text may support the language use of particular student groups.

The material provides some illustrations of the contributions of women and minorities to science and as role models. Introductory notes highlight multicultural perspectives and suggest that teachers “Tell students about the contribution to science and technology of people from diverse ethnic and cultural backgrounds” (p. T–32). Throughout the material, however, most of the contributions of women and minority scientists appear in special features. Science and Society sections relate chapter content to human activities sometimes focusing on the contributions of particular cultural groups (e.g. p. 246–247s). The Historical Notebook feature emphasizes historical contributions of particular cultural groups (e.g., p. 241s). The Career Corner feature briefly describes a scientific occupation related to the chapter content and includes a photograph of a scientist; in some instances, the scientist is a woman and minority (e.g., p. 606s). Multicultural Perspectives are general directions in teacher notes for projects related to the chapter content in which students often research particular characteristics of a cultural group. For example, one Multicultural Perspectives feature describes the work of Ynez Mexia, a woman botanist who collected plant specimens in isolated locations of North and South America. The feature asks students to read further about her work collecting plant specimens (p. 241t). All of these sections highlighting cultural contributions are interesting and informative but may not be seen by students as central to the material because they are mostly presented in sidebars and teacher notes.

The material suggests multiple formats for students to express their ideas during instruction, including individual investigations (e.g., p. 99st, Skills WorkOut), journal writing (e.g., p. 534t, Writing About the Photograph), laboratory investigations (e.g., p. 102st, Activity 5), cooperative group activities (e.g., p. 247t, Cooperative Learning), whole class discussion (e.g., p. 99t, Discuss), essay questions (e.g., p. 101st, Check and Explain, item 3), creative writing (e.g., p. 542t, Writing Connection), report writing (e.g., p. 551t, STS Connection), making models (e.g., p. 538t, Class Activity), and visual projects (e.g., p. 544t, Art Connection). In addition, multiple formats are suggested for assessment, including essay (e.g., p. 558st, Check Your Understanding, item 8), concept mapping (e.g., p. 109st, Make Connections, item 1), portfolio (e.g., p. 552t, WrapUp), creative writing (e.g., p. 247t, WrapUp), and visual projects (e.g., p. 101t, WrapUp). However, the material does not usually provide a variety of alternatives for the same task in either instruction or assessment.

The material does not routinely include specific suggestions about how teachers can modify activities for students with special needs. However, the Teacher’s Edition and supplementary materials (including reinforcement, enrichment and review worksheets, activities and laboratory investigations) provide additional activities and resources for students of specific ability levels. Teacher’s notes at the beginning of each chapter provide additional activities for limited English proficiency, at-risk, and gifted students (e.g., p. 92At, Individual Needs), and give ability level designations (core, standard, and enriched) for all chapter components (e.g., p. 236Bt, Chapter 12 Planning Guide). For Spanish speakers, there is a Spanish Supplement, which translates chapter summaries and the glossary, and Spanish Section Reviews (worksheets). However, the placement of some supplemental resources in individual booklets separate from the main text may discourage their use, and the special needs codes at the beginning of chapters may discourage teachers from using those activities with all students when appropriate.

The material provides some strategies to validate students’ relevant personal and social experiences with scientific ideas. Some text sections intersperse brief references to specific, personal experiences students may have had that relate to the presented scientific concepts (e.g., p. 487s). In addition, some tasks ask students about particular, personal experiences they may have had or suggest specific experiences they could have. For example, a Skills WarmUp asks students to approximate the number of fruits and vegetables that they ate the previous week and then to identify where the energy in the produce originally came from (p. 97st). However, the material rarely encourages students to contribute relevant experiences of their own choice to the science classroom, and sometimes it does not adequately link the specified personal experiences to the scientific ideas being studied (e.g., p. 100st, Skills WorkOut). Overall, support is brief and localized.