High School Biology Textbooks: A Benchmarks-Based Evaluation

Biology: Visualizing Life. Holt, Rinehart and Winston, 1998

Matter and Energy Transformations: Instructional Analysis

I: Providing a Sense of Purpose
Conveying unit purpose Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. A problem, question, representation (or otherwise identified purpose) is presented to students.
  2. The problem, question, representation (or otherwise identified purpose) is likely to be comprehensible to students.
  3. The problem, question, representation (or otherwise identified purpose) is likely to be interesting and/or motivating to students.
  4. Students are given an opportunity to think about and discuss the problem, question, representation (or otherwise identified purpose).
  5. Most lessons are consistent with the stated purpose and those that are not are explicitly labeled as digressions.
  6. The material returns to the stated purpose at the end of the unit.

Rating = Poor
The material meets no indicators.

Indicator 1: Not met
The unit and chapter openers do not provide a problem, question, representation (or otherwise identified purpose) for the students. Typically, units begin with a colorful two-page photograph, a list of the chapters included in the unit, and a few boxes of text. For unit three (pp. 250–251s), text boxes describe how the Earth is a greenhouse. Another text box, called “Looking Ahead,” raises some questions and refers students to pages where the questions are treated:

  • What might someone like Carmen Cid do for you or your future children? See Career Opportunities: Environmental Science, page 267.
  • How might you and other life-forms be affected if the Earth gets much warmer? See page 293.
  • How can you help solve environmental problems? See pages 301–304.
  • How can the loss of atmospheric ozone be slowed? See Science, Technology, and Society: Can the Ozone Layer Be Saved? pages 308–309.

p. 251s

However, the questions deal with a very small number of topics covered in the unit and do not provide a purpose for the unit as a whole. Nor do these questions frame chapters within units. The chapters also begin with a colorful one-page photograph and a list of the chapter sections. For example, Chapter 5: Energy and Life, opens with a photograph of impalas running across wetlands in Botswana (p. 76s). An Author’s Rationale, which appears below the picture, describes the contents but not the purpose of the chapter. Unfortunately, neither the teacher’s guide nor the student text presents a purpose for the chapter.

Indicator 2: Not met
Since there are no unit or chapter purposes clearly stated for the students, the question of comprehensibility cannot be addressed.

Indicator 3: Not met
Again, since there are no unit or chapter purposes clearly stated for the students, the question of whether students would be interested and motivated cannot be addressed.

Indicator 4: Not met
Again, since there are no unit or chapter purposes clearly stated for the students, the question of whether students are asked to think about such purposes cannot be addressed.

Indicator 5: Not met
Again, since there are no unit or chapter purposes clearly stated for the students, the question of whether lessons are consistent with a purpose cannot be addressed.

Indicator 6: Not met
Again, since there are no unit or chapter purposes clearly stated for the students, the question of whether the material returns to the stated purpose at the end of the unit cannot be addressed.

Conveying lesson/activity purpose Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material conveys or prompts teachers to convey the purpose of the activity to students.
  2. The purpose is expressed in a way that is likely to be comprehensible to students.
  3. The material encourages each student to think about the purpose of the activity.
  4. The material conveys or prompts teachers to convey to students how the activity relates to the unit purpose.
  5. The material engages students in thinking about what they have learned so far and what they need to learn/do next at appropriate points.

Rating = Poor
The material meets one out of the five indicators.

Indicator 1: Mostly met
The material consistently provides a purpose for readings and laboratory activities, but it only sometimes provides a purpose for teacher demonstrations.

Readings. Two features can help to convey the purpose of readings to students:

Laboratory activities found in the back section of the text consistently provide a purpose in the teacher’s guide and a list of objectives, as well as either a Background or a Situation for the students. Situations provide real-life contexts for the laboratories, while Backgrounds provide useful information for the activities. An example of a laboratory in which the purpose is clearly provided is Exploration 5A: Measuring the Rate of a Process. In the Situation, students are told that they are environmental engineers and that their job is to investigate which color of plastic will promote the highest rate of photosynthesis (p. 764s).

Teacher demonstrations. Of five demonstrations described in chapter 5 (pp. 77t, 78t, 79t, 85t, and 87t), two offer purposes. In the directions for Demonstration: Constructing Models, text for the teacher says the following:

...To show students how scientists today think enzymes function, show the class several gloves, only one of which fits your hand. Tell students that an enzyme and its substrate work more like a hand and a glove....

p. 80t

Similarly, the teacher directions for Demonstration: Determining the Validity of a Claim suggest the purpose of the activity by saying, “Students should determine whether a plant growth light significantly benefits the particular plants used in the demonstration” (p. 87t).

Indicator 2: Not met
The introductory paragraphs and section objectives often include technical vocabulary—for example, “activation energy,” “enzyme,” “substrate” (p. 77s), and “trophic levels” (p. 253s)—that may not be comprehensible to students who have not already studied the topic. The tasks described in the Backgrounds and Situations in the laboratories in the back section of the text also sometimes include terminology that may not be comprehensible to students who have not already studied the topic—for example, “ATP,” “NADPH,” “intensity and wavelength of light,” and “ATP synthesis” (p. 768s).

Indicator 3: Not met
Students are not asked to think about the purpose of the readings, demonstrations, or laboratory activities.

Indicator 4: Not met
The material does not convey or prompt teachers to convey how the activities are related to a unit or chapter purpose.

Indicator 5: Not met
None of the purposes provided in introductory paragraphs, section objectives, teacher demonstrations, or laboratory activities in the back section of the book engages students in thinking about what they have learned so far and what they need to learn/do next.

Justifying lesson/activity sequence Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material includes a logical or strategic sequence of activities.
  2. The material conveys the rationale for this sequence.

Rating = Fair
The material somewhat meets the first indicator but does not meet the second.

Indicator 1: Somewhat met
In its treatment of this topic, the text moves from presenting transformations of matter and energy at the molecular level (in chapter 2) to the cellular and organism levels (in chapter 5) to the ecosystem level (in chapter 14) and lastly to the human level (in unit six). The logic of this sequence is difficult to perceive, given that students are most familiar with the human organism. Similarly, while starting from the molecular level may be helpful to a chemist, it may not appear logical to students who have not yet studied chemistry.

Looking at the sequence of topics within chapters, it is sometimes possible to discern a logical sequence. For example, in Chapter 14: Ecosystems, the sections are arranged in a logical order: What Is an Ecosystem?, Cycles Within Ecosystems, and Kinds of Ecosystems. This sequence moves from general information about ecosystems to consideration of specific ecosystems.

Topics within sections are also sometimes organized logically. For example, the first section in Chapter 14, What Is an Ecosystem?, begins with State of Our World, which presents the idea that, because of changes humans have made to the environment, Earth may become unable to support its inhabitants. The next topic section defines “ecology” and “ecosystems,” while the third topic section explains that, to preserve the world, students need to study the complex topic of ecology. Now, presumably motivated and somewhat informed about the general ideas of ecology, students read in the next topic section about important concepts related to energy flow in ecosystems. The last topic in this first section of the chapter discusses the question “How Many Trophic Levels Can an Ecosystem Contain?”

However, the sequence is sometimes less coherent. For example, Chapter 5: Energy and Life begins with a section on Cells and Chemistry. This builds on the information on basic chemistry that was presented three chapters earlier in chapter 2. Section 5-2: Cells and Energy, first presents how cells release and use energy and then moves to a discussion of how energy flows from the sun through the living world. Section 5-3 presents details about photosynthesis, which has been mentioned several times earlier (e.g., on pages 52s and 77s). Section 5-4 presents Cellular Respiration. Throughout the chapter, the discussion of the processes moves back and forth between the cellular and organism levels, mentioning such organisms as humans (pp. 77s and 91s), a potato plant (p. 78s), a cat and seals (p. 81s), and a cow (p. 90s). The ecosystem level is even included on page 84s, where text and photographs present Energy Flow in the Living World.

Indicator 2: Not met
The material does not convey a rationale for the sequence of the chapters or the topics within the chapters. Although the opening of each chapter includes a section called Author’s Rationale, this section does not provide a rationale for the sequence. It merely explains what topics are included in the chapter. For example, the Author’s Rationale for chapter 5 says the following:

In this chapter, students are given an overview of metabolism without a lot of chemical terminology. The answers to three simple questions summarize this chapter.

  • How does energy flow through the living world?
  • How do plants capture energy from the sun?
  • How do we obtain this energy when we eat plants (or the animals that ate plants)?

Students will need to master the idea that energy-boosted electrons moving from one molecule to another are being used to drive proton pumps and make ATP.

p. 76t

The reason for the sequence of lessons in the chapter is not presented.

There is one effort to justify the order of topics: the Author’s Rationale for chapter 2 says, “Since the most life-defining characteristics are determined at the molecular level, some basic chemistry is introduced here” (p. 22t). However, with only one example, this indicator cannot be considered to be even partially met.

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II: Taking Account of Student Ideas
Attending to prerequisite knowledge and skills Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material alerts the teacher to specific prerequisite ideas or skills (versus stating only prerequisite topics or terms).
  2. The material alerts teachers to the specific ideas for which the prerequisites are needed.
  3. The material alerts students to prerequisite ideas or experiences that are being assumed.
  4. The material adequately addresses (provides instructional support for) prerequisites in the same unit or in earlier units (in the same or other grades). (The material should not be held accountable for addressing prerequisites from an earlier grade range. However, if a material does address such prerequisites they should count as evidence for this indicator.)
  5. The material makes adequate connections (provides instructional support for connections) between ideas treated in a particular unit and their prerequisites (even if the prerequisites are addressed elsewhere).

Rating = Poor
The material minimally meets one indicator.

Indicator 1: Not met
The material does not alert teachers to specific prerequisite ideas or skills. There is at the beginning of each chapter a feature on the student page called Review. This feature lists topics that students should review before continuing into the chapter. For example, the Review section for chapter 5 lists the following topics:

  • organic molecules (Section 2-3)
  • cell structure (Section 3-3)
  • the term energy

p. 76s

However, only topics are listed. Specific prerequisite ideas are not noted in these sections, and without more guidance it is unlikely that students will know exactly what parts of those listed sections should be reviewed.

Indicator 2: Not met
The material does not alert teachers to the specific ideas for which the prerequisites are needed.

Indicator 3: Not met
The material does not alert students to prerequisite ideas or experiences that are being assumed.

Indicator 4: Minimally met
The material mentions some prerequisite ideas or parts of prerequisite ideas but does not address them adequately. In the context of presenting unifying themes or principles as a framework for studying biology, for Theme 6: Matter, Energy, and Organization, the text presents the prerequisite idea that food provides the molecules that serve as fuel (but not building material) for all organisms:

Plants capture the energy of sunlight and use it to make complex molecules in a process called photosynthesis. These molecules then serve as the source of fuel for animals that eat them.

p. 18s

The same idea is presented later during discussion of Energy Flow in the Living World in chapter 5: “Organisms that cannot capture energy directly from sunlight get the energy for life by consuming food, which contains carbohydrates and other organic molecules” (p. 84s).

However, the use of food molecules for fuel and building materials by all organisms is mentioned:

Humans consume a great deal of carbohydrates; the seeds of rice, wheat, and corn supply about one-half of all the calories used by people. Animals store glucose in the form of long, branched chains called glycogen....Many organisms use [these] polysaccharides as structural molecules as well as for energy storage.

p. 30s

The idea that some chemical reactions (changes of configuration) require energy input while others release energy is presented in text and accompanied by graphs:

The graph shown in Figure 5-1b on the previous page represents a chemical reaction that releases energy. The breakdown of glucose is an example of this type of chemical reaction....Chemical reactions that build macromolecules such as proteins absorb energy. A chemical reaction that absorbs energy is represented by the graph in Figure 5-2b.

p. 78s

The text also presents the prerequisite idea that “Carbon and hydrogen are common elements of living matter” (pp. 26s and 29–30s) and shows examples of the related idea that “Carbon atoms...bond to several other carbon atoms in chains and rings to form large and complex molecules” (pp. 29–31s).

However, the following important prerequisite ideas are not addressed in the material:

Indicator 5: Not met
Adequate connections are not made between key ideas and their prerequisites. In the chapter 5 section Cells and Chemistry, in the sidebar Connection: Chapter 2, teachers are told to

Review the basic chemistry of covalent bond formation. Point out that most chemical reactions occurring in living things involve either the making or breaking of covalent bonds. Write the formulas for carbon dioxide, water, and glucose on the board. Emphasize the importance of these molecules in the metabolism of living things.

p. 78t

If a review of chapter 2 is conducted, students might review the prerequisite ideas that “All matter in the universe is composed of tiny particles called atoms” (p. 26s) and that

Of the 92 different kinds of atoms that occur naturally, carbon is the most closely associated with living things....carbon has four electrons in its outer energy level...a carbon atom seeks to fill that energy level by sharing electrons with other atoms. Carbon atoms form long chains that are the backbone of many different kinds of molecules. Molecules with carbon-carbon bonds are called organic molecules.

Organic molecules join together to form more complex molecules.

p. 29s

However, the directions in the Connection: Chapter 2 activity do not direct the teacher to focus on these prerequisites. Therefore, it cannot be assumed that any connection would be made.

Alerting teachers to commonly held student ideas Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material accurately presents specific commonly held ideas that are relevant to the key ideas and have appeared in scholarly publications (rather than just stating that students have difficulties with particular ideas or topics).
  2. The material clarifies/explains commonly held ideas (rather than just listing them).

Rating = Poor
The material meets no indicators.

Indicator 1: Not met
The material does not present specific commonly held ideas that are relevant to the key ideas and have appeared in the scholarly publications. In the teacher’s section in the front of the book, the purpose of a feature called Determining Prior Knowledge is given. The teacher reads that this feature “helps you assess how much your students know—and what misconceptions they may have—before you begin teaching” (p. T42). However, the material never alerts teachers to what these misconceptions are.

Teachers are not alerted to any of the following commonly held student ideas, identified in the research literature, that may interfere with students learning the key ideas:

  1. Students think that food is whatever nutrients organisms must take in if they are to grow and survive rather than those substances from which organisms derive the energy they need to grow and the material of which they are made (American Association for the Advancement of Science [AAAS], 1993, pp. 120, 342; Driver, Squires, Rushworth, & Wood-Robinson, 1994, p. 27).
  2. Students think that food is a requirement for growth rather than a source of matter for growth (AAAS, 1993, p. 343; Driver et al., 1994, p. 60).
  3. Students think that plants get their food from the environment (mainly from the soil) rather than manufacture it themselves (AAAS, 1993, p. 342; Driver et al., 1994, p. 30).
  4. Students think that plants have multiple sources of food rather than that plants make food from water and carbon dioxide in the air, and that this is their only source of food (AAAS, 1993, p. 342; Driver et al., 1994, pp. 31, 60).
  5. Students may think that organisms and materials in the environment are very different types of matter and are not transformable into each other (AAAS, 1993, p. 342).
  6. Students may not believe that a plant’s mass may increase mainly due to the incorporation of matter from carbon dioxide (a gas) (Driver et al., 1994, pp. 32, 39).
  7. Students may think that plants do not respire, or that they respire only in the dark (Driver et al., 1994, p. 34).
  8. Students tend to regard food that is eaten and used as a source of energy as belonging to a food chain, while the food that is incorporated into the body material of eaters is often seen as something different and is not recognized as the material that is the food at the next level (Driver et al., 1994, p. 35).
  9. Students may think that dead organisms “rot away”; they do not realize that the matter from the dead organisms is converted into yet other materials (AAAS, 1993, p. 343).
  10. Middle school students seem to know that some kind of cyclical process takes place in ecosystems. Some students see only chains of events and pay little attention to the matter involved in processes such as plant growth or animals eating plants. They think of the processes in terms of creating and destroying matter rather than in terms of transforming matter from one substance to another. Other students recognize one form of recycling through soil minerals but fail to incorporate water, oxygen, and carbon dioxide into matter cycles. Students may see no connection between the oxygen/carbon dioxide cycle and other processes involving the production, consumption, and use of food (AAAS, 1993, p. 343; Driver et al., 1994, p. 65).
  11. Students may think that matter and energy are converted back and forth in everyday (non-nuclear) phenomena (Schneps & Sadler, 1988).

One sighting was found that may actually support a misconception. The idea that plants make use of carbon dioxide from the air and water (Idea a1) is presented in chapter 22 in the context of Soils and Plant Growth:

Like you, plants require nutrients to grow. Plants obtain their nutrients from inorganic compounds such as carbon dioxide (CO2) and water (H2O). The carbon (C), oxygen (O), and hydrogen (H) in carbon dioxide and water are just three of the nutrients plants need. In Chapter 5, you learned that plants use the carbon, oxygen, and hydrogen from carbon dioxide and water in photosynthesis. But plants need more than just air and water to grow. Why do plants grow better in soil than they do in plain water? What is it about soil that helps plants grow?

Plants obtain nutrients from soil
The soil that surrounds a plant’s roots, as seen in Figure 22-13, provides many of the nutrients that the plant needs. Roots take up these nutrients as they take up water. Plants require relatively large amounts of the nutrients nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sulfur (S), and magnesium (Mg)....Other nutrients...are needed only in tiny amounts.

p. 420s

The information presented here is factual. However, this presentation does not state clearly that, in using carbon dioxide and water in photosynthesis, plants make the food which they later use for body structures and energy sources. Nor does it compare the amount of carbon dioxide and water plants need to the amount of soil nutrients they need. Therefore, this presentation may reinforce the misconception about plant nutrition that appears as number 3 in the list above.

Indicator 2: Not met
Since commonly held ideas are not presented, they cannot be clarified or explained.

Assisting teachers in identifying their students’ ideas Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material includes specific questions or tasks that could be used by teachers to identify students’ ideas.
  2. The questions/tasks are likely to be comprehensible to students who have not studied the topic and are not familiar with the scientific vocabulary.
  3. The questions/tasks are identified as serving the purpose of identifying students’ ideas.
  4. The material includes questions/tasks that ask students to make predictions and/or give explanations of phenomena (rather than focus primarily on identifying students’ meanings for terms).
  5. The material suggests how teachers can probe beneath students’ initial responses to questions or interpret student responses (e.g., by providing annotated samples of student work).

Rating = Poor
The material provides a few tasks that somewhat meet indicators 1, 2, and 3.

Indicator 1: Somewhat met
This material begins each chapter with a section in the teacher’s guide called Determining Prior Knowledge. Occasionally, the questions in these sections focus on the key biology ideas and might help teachers find out what their students think before they begin instruction. For example, the teacher is to show an apple and ask students “what process produced the carbohydrates that are stored in the apple” and “what the tree needs to be able to produce its fruit” (p. 76t). Another example has the teacher show the students a diagram of a simple food web and ask them to identify the “direction of energy flow” (p. 252t).

Indicator 2: Somewhat met
The tasks identified are likely to be comprehensible to students. However, there are too few of them to probe effectively for all the misconceptions students commonly have on this topic.

Indicator 3: Somewhat met
The questions/tasks given in Determining Prior Knowledge are identified as serving the purpose of identifying students’ ideas. In the teacher’s section at the front of the book, the teacher reads that this feature “helps you assess how much your students know—and what misconceptions they may have—before you begin teaching” (p. T42).

Indicator 4: Not met
The questions/tasks provided in the material do not ask students to make predictions or give explanations.

Indicator 5: Not met
The material offers no suggestions for how teachers can probe beneath students’ initial responses to questions. For example, the teacher’s guide does not tell the teacher to listen for his or her students’ responses, use ample wait time, or avoid correcting students’ ideas at this time. Without these warnings, it is unlikely that the questions provided will fully elicit student ideas. No suggestions are given that might help teachers interpret student responses in light of published misconceptions.

Addressing commonly held ideas Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material explicitly addresses commonly held ideas.
  2. The material includes questions, tasks, or activities that are likely to help students progress from their initial ideas, for example, by
    1. explicitly challenging students’ ideas, for example, by comparing their predictions about a phenomenon to what actually happens
    2. prompting students to contrast commonly held ideas with the scientifically correct ideas, and resolve differences between them
    3. extending correct commonly held ideas that have limited scope.
  3. The material includes suggestions to teachers about how to take into account their own students’ ideas.

Rating = Poor
The material meets no indicators.

Indicator 1: Not met
The material does not explicitly address any commonly held student ideas for the matter and energy transformations topic.

Indicator 2: Not met
The material does not include any questions, tasks, or activities that are likely to help students progress from their initial ideas.

Indicator 3: Not met
The material does not include suggestions to teachers about how to take into account their own students’ ideas.

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III: Engaging Students with Relevant Phenomena
Providing variety of phenomena Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Phenomena could be used to support the key ideas.
  2. Phenomena are explicitly linked to the relevant key ideas.

Rating = Poor
Since the rating scheme depends on how many phenomena meet both of the indicators, the report for this criterion is organized to reflect the overall rating rather than each indicator judgment.

This material provides only one phenomenon to support a key idea related to the flow of matter and energy, and this phenomenon is not linked to this key idea. Students chew a cracker until they notice a sweet taste. Then the teacher is to explain that enzymes in the saliva break down starchy foods (p. 77t). Students’ attention is not focused at all on the idea that the sweet taste is the sugars that made up starch formerly and that these pieces will be further broken down and reassembled into the students’ own body structures. Thus, the opportunity is missed for explicitly linking this phenomenon with the key idea that “Other organisms break down the stored sugars or the body structures of the plants they eat...into simpler substances, reassemble them into their own body structures, including some energy stores” (Idea c1).

Another missed opportunity occurs when students investigate which color of light promotes the highest rate of photosynthesis (pp. 764–765s). This activity focuses on the idea that plants need light to grow and only certain parts of light are useful to a plant. This investigation could be explicitly linked to the key idea that “Plants transfer the energy from light into ‘energy-rich’ sugar molecules” (Idea a2), but such a link is not made.

Providing vivid experiences Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Each firsthand experience is efficient (when compared to other firsthand experiences) and, if several firsthand experiences target the same idea, the set of firsthand experiences is efficient. (The efficiency of an experience equals the cost of the experience [in time and money] in relation to its value.)
  2. The experiences that are not firsthand (e.g., text, pictures, video) provide students with a vicarious sense of the phenomena. (Please note that if the material provides only firsthand experiences, this indicator is not applicable.)
  3. The set of firsthand and vicarious experiences is sufficient.

Rating = Poor
Since the rating scheme depends on how many phenomena meet all of the indicators, the report for this criterion is organized to reflect the overall rating rather than each indicator judgment.

The material meets no indicators. Given that only one phenomenon was provided and that it was not linked with a key idea, there is essentially nothing to be judged for vividness.

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IV: Developing and Using Scientific Ideas
Introducing terms meaningfully Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material links technical terms to relevant experiences that develop the idea as the term is used (rather than just having students learn definitions of terms).
  2. The material restricts the use of technical terms to those needed to communicate intelligibly about key ideas.

Rating = Poor
One indicator is somewhat met.

Indicator 1: Somewhat met
The material attempts to link some of the technical terms presented to relevant experiences. For example, ATP is compared to money in the bank or “energy currency,” and the burning of food is compared to the burning of a campfire log (pp. 82–83s). Sometimes examples are provided to make the terms more useful to students. For example, when the term “carnivore” is introduced, the text says, “Tigers, hawks, weasels, pelicans, and killer whales are carnivores” (p. 257s). Mostly, however, technical terms such as “carotenoids,” “thylakoid,” “NADPH,” “protein channel,” “Calvin cycle” (pp. 85–89s), “Krebs cycle,” “glycolysis,” “electron transport chain,” “pyruvic acid,” “oxidative respiration,” “lactic acid,” “ethyl alcohol,” and “feedback inhibition” (pp. 90–94s) are introduced without enough elaboration to be understandable to students.

Indicator 2: Not met
Many of the technical terms presented, such as “carotenoids,” “thylakoid,” “NADPH,” “protein channel,” “Calvin cycle” (pp. 85–89s), “Krebs cycle,” “glycolysis,” “electron transport chain,” “pyruvic acid,” “oxidative respiration,” “lactic acid,” “ethyl alcohol,” and “feedback inhibition” (pp. 90–94s) are beyond what is needed for intelligible conversation about the key ideas. In three sections examined for this criterion (5-1: Cells and Chemistry, 5-3: Photosynthesis, and 14-1: What Is an Ecosystem?), almost 50 technical terms were used. Less than a quarter of these are necessary to communicate intelligibly about the key ideas.

Representing ideas effectively Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Representation is accurate (or, if not accurate, then students are asked to critique the representation).
  2. Representation is likely to be comprehensible to students.
  3. Representation is explicitly linked to the real thing.

Rating = Poor
Since the rating scheme depends on how many representations meet all of the indicators, the report for this criterion is organized to reflect the overall rating rather than each indicator judgment.

The material has hardly any representations that are accurate, comprehensible, and explicitly linked to the real thing being represented. Thus, little support is provided to clarify the key ideas for students.

One representation was identified that satisfies the three indicators: to clarify the idea that “At each link in a food web, some energy is stored in newly made structures but much is dissipated into the environment as heat” (Idea d2), the text provides a diagram to represent the energy loss at each trophic level in an ecosystem (p. 258s). The caption explains the representation:

This ecological pyramid shows the amount of energy (indicated by red numbers) at each of four trophic levels in an ecosystem. There is 1,000 times more energy stored in grass at the first level than in hawks at the fourth trophic level.

p. 258s

The figure uses pictures of grasses, a mouse, a snake, and a hawk (rather than such terms as “producers,” “herbivores,” “carnivores,” and “top carnivore”) to clarify the kinds of organisms at each trophic level. The text links the representation with the real thing in two paragraphs:

In the 1950s, the ecologist Howard Odum determined how much energy was present at each trophic level in a Florida stream ecosystem. He captured animals and plants, measured their energy content, and built a model of how energy passed through the ecosystem. Odum found that when a herbivore eats a plant, only about 10 percent of the energy present in the plant’s molecules ends up in the herbivore’s molecules. The other 90 percent of the energy is “lost,” some as the cost of doing work (breathing, moving, chewing) and much more as heat. Likewise, when a carnivore eats the herbivore, only 10 percent of the energy in the herbivore goes toward making carnivore molecules. At each trophic level, the energy stored in the organisms is about one-tenth that of the level below it.

One way ecologists show the declining amount of energy at higher trophic levels is by drawing a diagram called an ecological pyramid, shown in Figure 14-7. Because energy diminishes at each successive trophic level, few ecosystems can contain more than five trophic levels. Also, organisms at higher trophic levels tend to be less numerous than those at lower trophic levels. On the African plains, for instance, there are about 1,000 zebras, gazelles, and wildebeest for each lion.

p. 258s

Unfortunately, some representations include inaccuracies that are not critiqued by students. A diagram showing the flow of energy through food chains explains that “Light energy streaming from the sun...is converted into carbohydrates by plants” (p. 84s). Since energy cannot be transformed into matter in chemical reactions, this is inaccurate. This type of error also occurs in a Graphic Organizer which explains that “Plants produce food (energy) for themselves and other organisms” (p. 255t). Some representations are missing crucial information and are not critiqued by students. For example, in the diagram of the carbon cycle (p. 262s), death and decomposition are mentioned, but no mechanism for the process is shown and no bacteria or microbes are shown. Decomposition is a mysterious process in which things seem to just go away. Lastly, an analogy comparing the carbon, nitrogen, and water cycles to the industrial recycling of newspapers, aluminum, and plastic (p. 259s) oversimplifies the processes that occur in nature. Throughout industrial recycling, aluminum remains aluminum and paper remains paper. But in nature carbon dioxide can become part of sugar molecules, and later the atoms can be rearranged again to become part of a cell wall. Likewise, nitrogen can become part of a DNA molecule. Although industrial recycling could serve to start students thinking about how atoms are rearranged in natural processes, students are never asked to critique the analogy or discuss the extent of its usefulness.

Demonstrating use of knowledge Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material consistently carries out (or instructs teachers to carry out) the expected performance (e.g., the student text explains a particular phenomenon using the kinetic molecular theory). (Teacher’s guides often include responses to questions posed in the student text. If the material does not instruct the teacher to use the answers to model the use of knowledge, such responses do not count as instances of modeling.)
  2. The performance is step-by-step.
  3. The performance is explicitly identified as a demonstration of the use of knowledge or skill.
  4. The material provides running commentary that points to particular aspects of the demonstration and/or criteria for judging the quality of a performance.

Rating = Poor
The material meets no indicators, since it does not demonstrate how the key ideas related to the flow of matter and energy can be used to explain phenomena or solve problems.

Providing practice Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material provides a sufficient number of tasks in a variety of contexts, including everyday contexts. (In order to determine whether the task/question addresses the actual substance of the key idea, reviewers will need to consider both the question and the expected response in the teacher’s guide.)
  2. The material includes novel tasks.
  3. The material provides a sequence of questions or tasks in which the complexity is progressively increased.
  4. The material provides students first with opportunities for guided practice with feedback and then with practice in which the amount of support is gradually decreased.

Rating = Poor
Since the rating scheme depends on how many practice tasks meet all of the indicators, the report for this criterion is organized to reflect the overall rating rather than each indicator judgment.

The material provides very few opportunities for students to practice using the key ideas related to the flow of matter and energy. For the idea that “Plants transfer the energy from light into ‘energy-rich’ sugar molecules” (Idea a2), students are asked to complete a concept map (p. 96s, question 3). For the idea that “Plants get energy...by oxidizing the sugar molecules” (Idea b2), students are asked, “Do plants perform cellular respiration?” (p. 96s, question 15). For the idea that “At each link in a food web, some energy is stored...but much is dissipated into the environment as heat” (Idea d2), students are asked, “Explain why most ecosystems usually can contain no more than five trophic levels” (p. 270s, question 8). With just these few questions, these key ideas are not adequately practiced.

Other ideas are not practiced at all, such as the following:

None of the few practice tasks provided are novel. In no case is there a sequence of questions or tasks in which complexity progressively increased. No guided practice with feedback is provided.

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V: Promoting Students’ Thinking about Phenomena, Experiences, and Knowledge
Encouraging students to explain their ideas Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Material routinely encourages students to express their ideas.
  2. Material encourages students not only to express but also to clarify, justify, and represent their ideas (a material is not expected to encourage students to clarify, justify, and represent ideas each time they are asked to express their ideas; however, in the course of teaching a particular key idea the material should provide students with opportunities to clarify, justify, and represent ideas).
  3. Material provides opportunities for each student (rather than just some students) to express ideas.
  4. Material includes specific suggestions on how to help the teacher provide explicit feedback to students or includes text that directly provides students with feedback.
  5. Material includes suggestions on how to diagnose student errors, explanations about how these errors may be corrected, and recommendations for how students’ ideas may be further developed.

Rating = Poor
The material meets no indicators.

Indicator 1: Not met
The material does not routinely encourage students to express their ideas. Only one task was identified that might elicit students’ own ideas. This task appears in the Reteaching feature in Section 14-2: Cycles Within Ecosystems:

Have students develop concept maps for each of the cycles in this section. (Answers will vary but should include the key concepts of each nutrient cycle and the names of representative organisms. Students should show that they understand how the cycles are balanced.)

p. 262t

Section Review and Chapter Review questions, which provide the correct answer, were not considered. The focus on the correct answer suggests that the questions are not really designed to elicit students’ own ideas.

Indicator 2: Not met
The single example of having students develop concept maps about nutrient cycles (page 262t) does allow students to represent their ideas. However, the students are not asked to clarify or justify their concept maps.

Indicator 3: Not met
Opportunities are not provided for each student to express ideas. Even in the single example noted (the concept maps about nutrient cycles on page 262t), it is not clear that each student will express his or her ideas.

Indicator 4: Not met
The material does not give specific suggestions to help the teacher provide explicit feedback to students, nor does the text provide such feedback.

Indicator 5: Not met
The material does not include suggestions on how to diagnose student errors, explanations about how those errors may be corrected, or recommendations for how students’ ideas may be further developed.

Guiding student interpretation and reasoning Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material includes specific and relevant tasks and/or questions for the experience or reading.
  2. The questions or tasks have helpful characteristics such as
    1. framing important issues
    2. helping students to relate their experiences with phenomena or representations to presented scientific ideas
    3. helping students to make connections between their own ideas and the phenomena or representations observed
    4. helping students to make connections between their own ideas and the presented scientific ideas
    5. anticipating common student misconceptions
    6. focusing on contrasts between student misconceptions and scientific alternatives.
    Please note that while a single high quality task or question sequence might have only one of these characteristics, the set of sightings should exhibit several of them.
  3. There are scaffolded sequences of questions or tasks (as opposed to separate questions or tasks).

Rating = Poor
One indicator is somewhat met.

Indicator 1: Somewhat met
The material includes specific questions at the end of each text section in a feature called Section Review. This feature provides several questions about the content of that section. Three such questions (and answers) were found that are relevant to the key ideas:

Question: Compare and contrast the roles of plants and animals in the flow of energy in the living world.

Suggested Response: Plants use the sun’s energy to produce carbohydrates. The carbohydrates provide energy for plant-consuming animals. These animals may be eaten by other animals, providing them with energy.

p. 84st, question 4

Question: Explain the important role producers play in ecosystems.

Suggested Response: Producers are the fundamental source of nutrition in an ecosystem.

p. 258st, question 2

Question: Suggest an explanation for why there are fewer lions than zebras on the African plains.

Suggested Response: Because available energy diminishes by approximately 90 percent at each successive trophic level, organisms at higher levels, such as lions, tend to be fewer in number than organisms at lower trophic levels, such as zebras.

p. 258st, question 4

All of these questions require students only to recall information from the text.

No questions focusing on key ideas were noted in teacher demonstrations or laboratory investigations.

Indicator 2: Not met
None of the questions in the Section Reviews have helpful characteristics such as framing important issues, helping students make connections between their own ideas and the presented scientific ideas, or anticipating student misconceptions.

Indicator 3: Not met
None of the Section Reviews involve scaffolded sequences of questions, which could guide students from phenomena or their own ideas about phenomena to the scientific ideas. Instead, Section Reviews include only individual questions on a particular area.

Encouraging students to think about what they have learned Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material gives students an opportunity to revise their initial ideas based on what they have learned (without asking them explicitly to think about how their ideas have changed).
  2. The material engages (or provides specific suggestions for teachers to engage) students in monitoring how their ideas have changed, but does so infrequently in the unit.
  3. The material engages (or provides specific suggestions for teachers to engage) students in monitoring how their ideas have changed and does so periodically in the unit.

Rating = Poor
The material meets no indicators.

Indicator 1: Not met
The material does not give students an opportunity to revise their initial ideas based upon what they have learned.

Indicator 2: Not met
The material does not engage students in monitoring how their ideas have changed at one or a few points in the unit.

Indicator 3: Not met
The material does not engage students in monitoring how their ideas have changed periodically in the unit.

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VI: Assessing Progress

To assess students’ understanding of concepts at the end-of-instruction, Biology: Visualizing Life provides chapter tests in two formats in a separate Chapter Tests booklet. Test A items are all multiple-choice while Test B includes both multiple-choice and short response items. In addition, the material includes an Alternative Assessment task for each chapter (in the teacher’s guide) and a generic Portfolio Assessment that has students construct a concept map from each chapter (p. T39). All these assessment options are listed at the beginning of each chapter (e.g., p. 75B and p. 251B) and, for the first two criteria, were examined for chapters 5, 14, and 34—the chapters that treat the key ideas on matter and energy transformations most extensively. The material also includes a test generator to assist teachers in assembling tests; however, since most items that are relevant to the key ideas are included in the chapter tests, the bank generator was not examined.

Aligning assessment to goals Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The specific ideas in the key ideas are necessary in order to respond to the assessment items.
  2. The specific ideas in the key ideas are sufficient to respond to the assessment items (or, if other ideas are needed, they are not more sophisticated than key ideas and have been taught earlier).

Rating = Poor
Since the rating scheme depends on how many assessment tasks meet both of the indicators, the report for this criterion is organized to reflect the overall rating rather than each indicator judgment.

The material provides only four items that meet indicators 1 and 2. One of the key ideas—that energy decreases at each trophic level (but not that the decrease is due to energy given off as heat)—is necessary and sufficient to respond to the first three questions below. And the idea that carbon cycles through food webs is needed to respond to the last item.

The diagram represents the decrease

  1. in the number of organisms between lower and higher trophic levels.
  2. in available energy between lower and higher trophic levels.
  3. in diversity of organisms between lower and higher trophic levels.
  4. All of the above are represented.

pp. 82 and 223, Chapter Test A: Chapter 14, item 4

In going from one trophic level to the next above it

  1. the amount of usable energy remains constant.
  2. the amount of usable energy increases.
  3. the amount of usable energy decreases.
  4. diversity of organisms increases.

pp. 85 and 223, Chapter Test B: Chapter 14, item 7

Question: When food is very scarce, why is it smarter for people to eat grains rather than raise animals to eat?

Suggested Response: Animals are on higher trophic levels than plants. Consequently, it takes several pounds of grain to produce one pound of meat. The several pounds of grain could feed several people instead of producing a small amount of meat to eat. By eating grain rather than meat, people move to a lower trophic level and use food more efficiently.

pp. 87 and 223, Chapter Test B: Chapter 14, item 24

Wood decays, giving off carbon dioxide gas that is then used for photosynthesis by plants. This is an example of

  1. a nutrient cycle.
  2. a Krebs cycle.
  3. environmental air pollution that damages the ozone layer.
  4. All of the above are true.

pp. 86 and 223, Chapter Test B: Chapter 14, item 9

Other items focus on details that are not part of any of the key ideas (e.g., “Which of the following does not occur during one of the three stages of photosynthesis?,” p. 28, Chapter Test B: Chapter 5, item 6; “Which of the following is part of the nitrogen cycle?,” p. 83, Chapter Test A: Chapter 14, item 14) or on terms (e.g., “The process represented by the equation 6CO2 + 6H2O → C6H12O6 + 6O2 is called photosynthesis,” pp. 29 and 219, Chapter Test B: Chapter 5, item 15).

Testing for understanding Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Assessment items focus on understanding of key ideas.
  2. Assessment items include both familiar and novel tasks.

Rating = Poor
Since few assessment tasks were aligned to the key ideas, the report for this criterion is organized to reflect the overall rating rather than each indicator judgment.

One of the relevant assessment items described under the previous criterion requires application of key ideas (“When food is very scarce, why is it smarter for people to eat grains rather than raise animals to eat?”). This is clearly insufficient to assess understanding of the set of key ideas.

Using assessment to inform instruction Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material uses embedded assessment as a routine strategy (rather than just including occasional questions).
  2. The material assists teachers in interpreting student responses to diagnose what learning difficulties remain.
  3. The material provides specific suggestions to teachers about how to use the information from the embedded assessments to make instructional decisions about what ideas need to be addressed by further activities.

Rating = Poor
Since the material provides no tasks for this criterion, this report is organized to reflect the overall rating rather than each indicator judgment.

Biology: Visualizing Life does not make any claims about assessing students throughout instruction to diagnose students’ remaining difficulties and modify the instruction accordingly.

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VII: Enhancing the Science Learning Environment
Providing teacher content support Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Alerts teachers to how ideas have been simplified for students to comprehend and what the more sophisticated versions are (even though students are not required to understand the more sophisticated versions).
  2. Provides sufficiently detailed answers to questions in the student book for teachers to understand and interpret various student responses.
  3. Recommends resources for improving the teacher’s understanding of key ideas.

Rating = 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 usually briefly elaborate on one or a few student text concepts (e.g., p. 90t, Exchanging Gases) or briefly explain peripheral information (e.g., p. 92t, Matter of Fact). Overall, the teacher content support is brief, localized, and fragmented.

The material does not usually provide sufficiently detailed answers to questions in the student book to help teachers understand and interpret various student responses. While most answers include expected scientific responses, little, if any, additional information is provided for teachers to field potential student questions or difficulties (e.g., p. 84t, Answers to Section Review, answer 4). In addition, some answers are brief and require further explanation (e.g., "blue" [p. 764t, Analysis, answer 15]). Some questions go unanswered (e.g., p. 252t, Determining Prior Knowledge).

The material provides minimal support in recommending resources for improving the teacher's understanding of key ideas. The material lists resources available within supplemental program materials in introductory notes (pp. T26–T41) and in the "Lesson Resources" at the beginning of each chapter (e.g., pp. 251A–251Bt). While these resources might help teachers improve their understanding of the key ideas, the lists lack annotations about what kind of specific information the resources provide.

Encouraging curiosity and questioning Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. Includes suggestions for how to encourage students’ questions and guide their search for answers, respect and value students’ ideas, raise questions of evidence, and avoid dogmatism.
  2. Provides examples of classroom interactions—e.g., dialogue boxes, vignettes, or video clips—that illustrate appropriate ways to respond to student questions or ideas, etc.

Rating = Minimal support is provided.

The material provides a few suggestions for how to encourage students' questions and guide their search for answers. A few tasks ask students to generate questions (e.g., p. 91t, Community Connection) and sometimes form responses (e.g., p. 95t, Alternative Assessment).

The material provides a few suggestions for how to respect and value students' ideas. Some tasks explicitly elicit student ideas (e.g., p. 90t, Active Reading). In addition, teacher notes state that multiple student answers should be acceptable for some tasks (e.g., pp. 788–789t, Analysis, answers 12–14). Similarly, appendix notes about concept mapping state that students may see "different relationships between certain concepts" (p. 839s).

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?" However, 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. 97s, Reviewing Themes, item 22; p. 765s, Analysis, items 9, 11, 12 and 14).

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 all people can participate (e.g., pp. 5–15s). The material also discusses current issues in biology related to chapter content (pp. 716–717st, Science, Technology and Society). In each Chapter Review, students are asked to read and respond to popular science articles (e.g., p. 97t, Discovering Through Reading, item 29). 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 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 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., pp. 788–789st, Exploration; p. 83t, Problem Solving).

Supporting all students Indicators of meeting the criterion (click to show/hide)

Indicators of meeting the criterion

  1. The material avoids stereotypes or language that might be offensive to a particular group.
  2. The material illustrates the contribution of women and minorities to science and brings in role models.
  3. The material suggests alternative formats for students to express their ideas during instruction and assessment.
  4. The material includes specific suggestions about how teachers can modify activities for students with special needs.
  5. The material provides strategies to validate students’ relevant personal and social experiences with scientific ideas.

Rating = Some support is provided.

The material generally avoids stereotypes or language that might be offensive to a particular group. For example, photographs and illustrations include a diverse cultural mix of students and adults (e.g., pp. 10s, 77s, 705s), but the number of photographs that include people throughout the material are few.

The material provides some illustrations of the contributions of women and minorities to science and as role models. Most of the contributions of women and minority scientists, however, appear in separate sections entitled Career Opportunities, Multicultural Perspectives and Historical Perspectives. Career Opportunities describe the careers of women or minority scientists, give information for students to learn more about the careers and provide suggestions to the teacher for class discussions. For example, one Career Opportunities feature discusses the life and work experiences of ecologist, Dr. Carmen Cid (p. 267st). Multicultural Perspectives provide information about particular cultural groups related to the chapter content (e.g., p. 265t). Historical Perspectives sometimes describe the contributions of specific scientists, some of whom are women and minorities (p. 79t). All of these sections highlighting cultural contributions are interesting and informative, but some may not be seen by students as central to the material because they are presented in sidebars and teacher notes.

The material suggests multiple formats for students to express their ideas during instruction and assessment, including cooperative group activities (e.g., p. 84t, Closure), laboratory investigations (e.g., pp. 764–765s), whole class discussions (e.g., p. 76t, Determining Prior Knowledge), essay questions (e.g., p. 270st, Understanding Concepts, item 10; p. 87, Chapter Test B: Chapter 14, item 24) , concept mapping (p. 262t, Reteaching), visual projects (e.g., p. 94t, Reteaching), research projects (e.g., p. 97s, Life/Work Skills, item 26), and portfolio (e.g., p. 95t, Portfolio Assessment). 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 material includes a Reteaching feature (e.g., p. 84t) "for additional instruction in a major concept of the section" (p. T43), and supplemental program resources provide additional activities and resources for students (for a description, see pp. T34–T35).

The material provides some strategies to validate students' relevant personal and social experiences with scientific ideas. Some text sections relate specific personal experiences students may have had to the presented scientific concepts (e.g., p. 77s). In addition, some features in teacher notes (e.g., p. 86t, Decision Making) ask students about particular personal experiences they may have had or suggest specific experiences they could have. However, the material rarely encourages students to contribute relevant experiences of their own choice to the science classroom. Overall, support is brief and localized.

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