High School Biology Textbooks: A Benchmarks-Based Evaluation

Biology: Principles & Explorations. Holt, Rinehart and Winston, 1998

Cell Structure and Function: 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. Chapter titles—for example, Nature of Cells (p. 24s)—indicate what will be covered in the chapter, but they do not state it explicitly as the purpose. The Chapter Theme conveys the intent of each chapter to the teacher—for example, “In this chapter, students will become acquainted with some precursor organisms that have become cell structures” (p. 24t)—but at no time are teachers instructed to share this intent with students. The Authors’ Rationale also informs the teacher about the intent of the chapter—for example, “Before tackling the broader concepts of ‘life,’ it is essential that students have a very good understanding of its smallest component parts—cells” (p. 24t)—but again, teachers are not asked to share that intent with the students.

Indicator 2: Not met
Since there is no clearly stated purpose for the students, the comprehensibility of such a purpose cannot be judged. Even if the titles of chapters were considered to be purposes, they are too broadly stated, and they use terms that would be unfamiliar to a student who doesn’t already understand the concepts.

Indicator 3: Not met
Once again, since there is no clearly stated purpose for the students, it is impossible to say if the purpose would be interesting and motivating for them. The colorful pictures at the beginning of each chapter convey no purpose, and the chapter titles are not interesting and motivating.

Indicator 4: Not met
Giving students an opportunity to think about and discuss the problem, question, representation (or otherwise identified purpose) is not a characteristic of the material. The Opening Demonstrations do not address the implied purpose for each chapter. For example, showing students “diagrams of typical cells, both animal and plant” (p. 24t) is designed to prepare students for the topics covered in the chapter; but it does not engage the students in a discussion about the implied purpose, “Nature of Cells.”

Indicator 5: Not met
All of the lessons in a chapter are related to the chapter title, but chapter titles are not explicitly stated as purposes.

Indicator 6: Not met
Without a stated purpose, there is no purpose to return to at the end of the chapter. Students may be asked to complete an activity designed to help them review the chapter content—for example, they are asked to make models of cells from “pipe cleaners, plastic foam, cardboard, etc.” (p. 48t)—but this activity is not related to a chapter purpose.

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: Met
Three features can help to convey the purpose of readings for students:

Indicator 2: Not met
Section Objectives include technical vocabulary such as “prokaryotes,” “eukaryotes,” “covalent bonds,” and “nucleic acids” that may not be comprehensible to students who have not already studied the topic. However, section titles do not include technical vocabulary.

Indicator 3: Not met
Students are not asked to think about section titles, opening paragraphs, or Section Objectives. Opening Questions—such as “Ask students what kind of a substance carbon is” (p. 34t); “Ask students to name the principal organic compounds of living systems and some of their uses” (p. 39t)—are intended to “[ask] a question about material that has been covered previously” (p. 44T) rather than to have students think about the purpose of the upcoming section.

Indicator 4: Not met
This is not a feature of this material since the material does not convey or prompt the teacher to convey how the material is tied to the unit purpose. Connections, a feature of the teacher notes, “discusses the ways in which a lesson topic relates to material the students have already learned in a previous chapter” (p. 47T); but these ways are neither related to the upcoming section nor to be conveyed to students.

Indicator 5: Not met
The material does not engage students at appropriate points in thinking about what they have learned so far and what they need to learn next. The Capsule Summary sidebars relate to the Section Objectives but do not serve this purpose:

Proteins are part of an organism’s structure. As enzymes, proteins increase the rate of chemical reactions within cells. The sequence of amino acids in a particular protein determines its shape, chemical properties, and function.

p. 36s

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
The information presented in chapter subsections containing the key ideas about cell structure and function appears to be logically sequenced. For example, the topic sequence for section 2-1 Cells: The Smallest Units of Life, presents general background information about the cell: the cell theory, a comparison of prokaryotes and eukaryotes, and the size of cells (pp. 25–28s). However, the chapter subsections are not sequenced logically within the chapter. The second subsection presents general information about atoms (2-2 The Chemistry of Living Cells, including the nature of atoms, types of bonds, the nature of water, and acids and bases [pp. 29–33s]). The third subsection presents information about the important biological macromolecules (2-3 Chemical Building Blocks of Cells, including carbohydrates, lipids, proteins, nucleic acids, and ATP [pp. 34–38s]). For the most part, the last subsection presents information about cellular organelles (2-4 The Interior of the Cell [pp. 39–48s]). The sequence of the chapter subsections describes the cell (2-1), the atom (2-2), macromolecules (2-3), and then returns to the cell (2-4). The topic of microscopes is briefly introduced in subsection 2-1 (p. 25s) and then returned to as a major component of subsection 2-4 (pp. 39–41s).

Furthermore, the presentation of key ideas within each topic is interrupted by more sophisticated and/or tangential information. For example, the section on the organelles of the cell focuses mostly on the names and details of the structures of the organelles (e.g., “Flagella are…complex cables of microtubules. Each flagellum consists of a circle of nine microtubules surrounding two central microtubules. This 9 + 2 arrangement is a fundamental feature of the flagella of eukaryotes” [p. 46s]).

Indicator 2: Not met
The material does not convey a rationale for the sequence of units or chapters or for the sequence of readings or other activities within chapters. Although each chapter begins with an Authors’ Rationale, this feature does not provide the logic for the sequence of topics or activities within the chapter. For example, the Authors’ Rationale for Chapter 2: Nature of Cells provides information on what students will study but not why:

Before tackling the broader concepts of “life,” it is essential that students have a very good understanding of its smallest component parts—cells. Thorough understanding of this critical component of life is achieved through discussion of why cells exist, followed by a hierarchical description of the elements that actually combine to compose cells. This discussion includes enough chemistry for students to understand cell structure and function and a description of the individual organelles. The rest of biology builds on these concepts.

p. 24t

Even when a purpose is provided for the information in the chapter, it is cast in vague terms and provides no rationale for the sequence of sections. No other features in this material provide such information to the teacher.

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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 fully meets no indicators, but indicator 4 is somewhat met.

Indicator 1: Not met
The material does not alert the teacher to specific prerequisite ideas or skills. While the teacher’s guide notes that the Review feature “identifies topics from earlier chapters that students should understand before beginning the new chapter” (p. 22T), this feature lists only topics, not specific ideas. For example, the Review feature for Chapter 2: Nature of Cells notes only one topic for review, namely, “characteristics of life (Section 1-3)” (p. 24s). There is no additional information about how this topic relates to any specific ideas taught in the chapter.

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

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

Indicator 4: Somewhat met
The material does not adequately address prerequisites in the same unit or in earlier units. The material presents only one prerequisite idea from physical science in Chapter 2: Nature of Cells. The prerequisite idea that “Atoms may stick together in well-defined molecules” [4D(6-8)/1] is stated in the text: “A compound is a group of atoms held together by chemical bonds” (p. 30s). However, the text does not further explain this idea; instead, it continues by discussing formulas and types of bonds. Other prerequisite ideas are not presented, such as:

Indicator 5: Not met
The material does not connect the prerequisite idea treated in the text to the key idea. The prerequisite idea that “Atoms may stick together in well-defined molecules” is stated in the text but is not used to explain the key idea that “The work of the cell is carried out by the many different types of molecules it assembles, mostly proteins” (Idea c).

A feature in the teacher’s guide called Connections attempts to link previously covered topics to ideas currently being learned; however, this feature does not appear in Chapter 2: Nature of Cells.

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 = Not rated
For the topic of cell structure and function, materials were not rated on this criterion because no research base outlines commonly held student ideas.

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 very few questions to help teachers identify students’ ideas. Two indicators are somewhat (but not fully) met.

Indicator 1: Somewhat met
The material includes two features that provide a few questions that could be used by the teacher to find out what students know before instruction begins. The Tapping Prior Knowledge feature includes the following relevant question: “What are some characteristics that all cells share?” (p. 24t). And the Opening Question feature includes the following relevant question: “Divide the class into groups of 3–5 students. Have the groups make lists of the things they think of as the functions of life. Discuss the lists in class” (p. 25t). However, these questions do not focus on the key ideas and are not sufficient to elicit students’ ideas on this topic.

Indicator 2: Somewhat met
The above questions are comprehensible but are insufficient to elicit students’ ideas on this topic.

Indicator 3: Not met
The questions are not identified as serving the purpose of identifying students’ ideas. Questions in the Opening Question feature ask about information that has been covered previously (as indicated on p. 44T) and usually have only one right answer given.

Admittedly, the teacher’s guide indicates that questions in Tapping Prior Knowledge “[help] you assess how much your students know—and what misconceptions they may have—before you begin teaching” (p. 44T). But the above questions are about the information treated in prior chapters rather than about possible misconceptions.

Indicator 4: Not met
These questions do not ask students to give explanations or to make predictions.

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/her students’ responses or to avoid correcting their ideas at this time. Without these warnings, it is unlikely that the questions provided will be used to elicit student ideas. And no suggestions are given that might help teachers interpret student responses.

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 = Not rated
For the topic of cell structure and function, materials were not rated on this criterion because no research base outlines commonly held student 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.

The material provides almost no phenomena to support the key ideas. While some phenomena were found that could be used to make key ideas credible, very few were explained using the key ideas. For example, for the key idea that cells have specialized parts for specific functions (Idea b), students observe prepared microscope slides of epithelial cells, human blood, and Elodea in a Laboratory Investigation (pp. 52–53s). Only one of the analysis questions focuses on the cells’ structures and how they are related to the functions:

How does the structure of each of the three kinds of cells that you observed relate to the function of each type of cell? Based on what you know about the organism each cell is from, how might each structure help that organism survive?

p. 53s, Analysis, question 2

Similarly, another Laboratory Investigation (pp. 72–73s) demonstrates diffusion, but it does not explain this concept in terms of the key idea that a cell is enclosed by a membrane that controls what enters and leaves the cell (Idea a).

A few other phenomena are presented in the teacher’s guide, but are not explained in terms of the key ideas. For example, a Teaching Tip explains that “Grass wilts if too much fertilizer is applied to it. Have students relate the concept of osmosis to this event” (p. 60t). However, the expected answer does not relate this phenomena to the control that the cell membrane has over what can enter and exit the cell (Idea a): “High salt concentrations in water around the roots and leaves cause an osmotic flow of water out of cells. Wilting is the result of the water loss” (p. 60t).

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 so few phenomena were explained using the key ideas, 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
The material meets no indicators.

Indicator 1: Not met
The material does not link new technical terms to relevant experiences. With few relevant phenomena, there seems to be little point to using the terms other than to have students learn their definitions. For example, terms like “organelle” and “cell membrane” (p. 26s) are defined in the abstract with no helpful examples given to make the terms concrete for students. Even when terms are linked to a representation, the representation is often incomprehensible and hence does not provide a helpful concrete experience to make the terms meaningful to students. For example, see the route of proteins diagram (Figure 2-21, p. 43s) and the sun as source of energy diagram (Figure 2-23, p. 45s).

Indicator 2: Not met
The material does not restrict the use of technical terms to those needed to communicate intelligibly about the benchmark ideas. For the key ideas cell structure and function, unnecessarily introduced terms include: “nuclear envelope,” “nuclear pore,” “peroxisomes,” “lysosomes,” “actin filaments,” “intermediate filaments,” “lumen,” “channels,” “cell surface markers,” “receptor protein,” and “phospholipid.”

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. As a result, little support is provided to clarify the key ideas for students.

Several representations show specialized parts of cells (e.g., Figures 2-19, 2-20, 2-22, and 2-24 on pp. 42–46s), but none relates the structure of the specialized part to its function (Idea b). The representations related to the idea that the cell membrane controls what can enter and exit the cell (Idea a) are typically cluttered with details that are beyond the scope of this key idea, such as Figure 3-2 (p. 56s). Three analogies are provided. For the idea that the cell membrane controls what can enter and exit the cell (Idea a), the cell membrane is compared to a house (p. 65s). For the idea that cells have specialized parts (Idea b), a cell is compared to the human body (p. 46t) and to a factory (p. 42t). Although each of these analogies has some potential to help clarify the two key ideas, none of the three asks students to consider the limitations of the analogies, such as how a cell is like and unlike the analogue. Without considering the limitations of analogies, students may overextend the analogy or misapply the relevant features of the analogy.

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.

Indicator 1: Not met
The material does not consistently demonstrate the use of key ideas or suggest how teachers could do so.

Indicator 2: Not met
No step-by-step demonstrations are provided.

Indicator 3: Not met
No demonstrations are identified as such.

Indicator 4: Not met
Because no demonstrations are provided, no running commentary that points to particular aspects of a demonstration is provided; nor does the material provide criteria for judging the quality of a performance.

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.

Two kinds of questions and tasks were considered for this criterion. These included Chapter Review questions and student tasks and questions within the chapter requiring application of ideas presented in the text. The material provides very few tasks for only one key idea: that cells have specialized parts for specific functions (Idea b). For example:

What function do organelles serve?

p. 28s, question 2

Name five organelles. Describe how each enables the cell to display the properties of life.

p. 48s, question 2

Are lysosomes in animal cells similar to central vacuoles in plant cells? Explain your answer.

p. 48s, question 3

Another question asks students to make a model of an organelle and present it to the class (p. 51s, item 27). Other questions focus on organelles but not on their functions. For example, one multiple choice question asks students to select organelles that are present in plants but not in animals (p. 49s, question 1).

No novel tasks are provided.

The material does not provide a sequence of questions or tasks in which the complexity is progressively increased.

The material does not first provide students with opportunities for guided practice with feedback and then provide them with practice in which the amount of support is gradually decreased.

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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. Very few questions/tasks were included that appear to be intended for having students express their own ideas (i.e., questions for which no correct answer is provided in the teacher’s guide). Students are asked to make concept maps of relevant terms (e.g., pp. 49st). While a single answer is provided, the teacher’s guide notes that it is only one possibility.

While questions were provided in Teaching Tips (e.g., pp. 38t, 41t, 44t, 48t, 60t), Chapter Closure (e.g., p. 48t), and Visual Strategy (pp. 33t, 37t, 41t, 43t, 47t), very few of these examples include questions specific to the key ideas. Many questions did not focus on these key ideas, while others asked questions that were beyond the scope of these key ideas.

Neither Section Review nor Chapter Review questions, which provide the correct answer, were considered. The focus on the correct answer suggests the questions are not really designed to elicit the students’ ideas.

Indicator 2: Not met
The Chapter Reviews ask students to make concept maps, which do give them a chance to represent their ideas; however, an answer is always provided (e.g., pp. 49st). Students are not asked to clarify or justify their concept maps.

Indicator 3: Not met
Since most of the questions do not apply to this criterion, it is not relevant that students are expected to write answers to those questions.

Indicator 4: Not met
The material does not include specific suggestions to help the teacher provide explicit feedback to students nor does the text do so.

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 and laboratory activity. Each text section includes a Section Review that provides three to four questions about its content. A few of these questions (and answers) are relevant to the key ideas:

Question: What function do organelles serve?

Suggested Response: Organelles compartmentalize the cell into functional areas.

p. 28st, question 2

Question: Name five organelles. Describe how each enables the cell to display the properties of life.

Suggested Response: Answers will vary. See pages 42–47 for possible answers.

p. 48st, question 2

Question: Are lysosomes in animal cells similar to central vacuoles in plant cells? Explain your answer.

Suggested Response: Lysosomes are similar to vauoles in that they contain liquid. They are dissimilar in that they contain digestive enzymes.

p. 48st, question 3

However, all of the above questions involve only recalling information from the text. Furthermore, questions are provided for only one of the key ideas: that cells have specialized parts for specific functions (Idea b).

While the material includes questions at the end of relevant laboratory investigations and some demonstrations, only one of the questions focuses on the key ideas. After observing a few examples of plant and animal cells through a microscope, students are asked to describe the shape and appearance of cells, how plant and animal cells are similar and different, as well as:

Question: How does the structure of each of the three kinds of cells that you observed relate to the function of each type of cell? Based on what you know about the organism each cell is from, how might each structure help that organism survive?

Suggested Response: Answers will vary. Chloroplasts allow plant cells to make their own food. The cell wall makes plant cells more rigid and gives them greater strength and protection. Animal cells are bound only by a plasma membrane that is more flexible than a cell wall; thus, animal cells can move more easily.

p. 53st, Analysis, question 2

Teaching Tips, Closure, and Visual Strategy features rarely have questions relevant to the key ideas.

Indicator 2: Not met
None of the questions in the Section Reviews has 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 involves scaffolded sequences of questions, which could guide students from phenomena or their own ideas about phenomena to scientific ideas. Instead, Section Reviews include only individual questions on a particular idea.

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 somewhat meets the first indicator.

Indicator 1: Somewhat met
The material gives students an opportunity to revise their initial ideas based on what they have learned. The teacher’s guide indicates that “Section Reviews help students check their content mastery” (p. 48T) and that “…test[s] should be reviewed by the student and incorrect responses should be corrected by the student before the test becomes part of the portfolio” (p. 49T). However, since students’ ideas are not solicited before instruction and most of the answers to the Section Review questions are included in the preceding text, it is not clear how these questions will encourage students to revise their initial ideas.

Indicators 2 and 3: Not met
The material does not engage students in monitoring how their ideas have changed.

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VI: Assessing Progress

To assess students’ understanding of concepts at the end of instruction, Biology: Principles & Explorations provides a test for each chapter and includes a generic Portfolio Assessment suggestion—to have students construct a concept map from each chapter (p. 49T). These options in chapters 2 and 3, the chapters that treat the key ideas about cell structure and function most extensively, were examined for the first two criteria.

At the beginning of the teacher’s guide, the developers state that “Chapter Reviews thoroughly evaluate content mastery” (p. 48T). However, in the Block Scheduling Guide that precedes each chapter (e.g., pp. 23A–23B, 53A–53B), the Chapter Reviews are not listed as assessment options and therefore were not examined for these criteria.

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.

Biology: Principles & Explorations provides only one question in Chapter Tests that assesses one of the key ideas for cell structure and function. For the idea that the cell membrane controls what can enter and exit the cell (Idea a), students are asked to complete this statement: “A plasma membrane is said to be ____________ permeable because it allows the passage of some solutes and not others” (Chapter Tests, pp. 8 and 127, question 15). Although this question states that cell membranes exhibit control over what enters and leaves the cell, the question only requires students to provide the term “selectively.” Even if students answer this question correctly, the teacher would not know whether or not the students understand this key idea.

The other questions provided do not focus on these key ideas. Many of the questions focus on the four main types of macromolecules, such as:

Which type of molecule makes up the cell membrane?

  1. carbohydrate
  2. nucleic acid
  3. lipid
  4. protein

Chapter Tests, pp. 4 and 127, question 9

Other questions focus on chemistry concepts, such as this question: “Atoms with unequal numbers of electrons and protons are called ions” (Chapter Tests, pp. 5 and 127, question 18).

Some questions ask students to label parts of a cell shown in a diagram (e.g., Chapter Tests, p. 5, questions 14–16). However, even questions that are related to labeling structures of the cell do not focus on the functions of these structures and therefore do not adequately assess students’ understanding of the idea that cells have specialized parts for specific tasks (Idea b).

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 no 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.

Of the relevant assessment items described under the previous criterion, none requires understanding of the key ideas. Clearly this is not sufficient to assess students’ understanding of the key ideas examined here.

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, the report is organized to reflect the overall rating rather than each indicator judgment.

Biology: Principles & Explorations does not make any claims about assessing students throughout instruction to diagnose their 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. 28t, Teaching Tip) or briefly explain peripheral information (e.g., pp. 46t and 59t, Did You Know?). 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 for teachers to 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. 70t, Themes Review, answer 23; p. 73t, Analysis Answers, answer 4). In addition, some answers are brief and require further explanation (e.g., p. 28t, Answers to Section Review, answer 2; p. 51t, Activities and Projects, answer 27). Some questions go unanswered (e.g., p. 24t, Tapping 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. 26T–41T) and in the “Program Resource Key” at the beginning of each chapter (e.g., p. 23Bt). 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. At the beginning and end of Laboratory Investigations, students are asked to write a question to explore in the experiment (e.g., p. 72s, Background, item 3) or to be studied in another investigation (e.g., p. 53s, Further Inquiry).

The material provides a few suggestions for how to respect and value students’ ideas. Introductory teacher notes about concept mapping give criteria for evaluation of maps but also state that “there is not a single correct map for an idea” (p. 51T). In addition, some tasks ask for student ideas (e.g., p. 25t, Opening Question) and teacher notes state that multiple student answers should be acceptable for some questions (e.g., p. 53t, Analysis Answers, answer 2; p. 73t, Analysis Answers, answer 4).

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. 71s, Readings, item 30; p. 73s, Inquiry, item 3).

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. 5–7s, 15–18s). The material also describes developments in scientific thinking about cell theory (pp. 25t and 39t, Historical Notes) and discusses related current issues in biology (p. 40t, Research Update). In each Chapter Review, students are asked to read and respond to popular science articles (e.g., p. 71s, Readings, 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 cooperative group activities (e.g., p. 25t, Opening Question; p. 51s, Activities and Projects, item 27).

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. 13–14s, 48s, 65s), but the number of photographs that include people throughout the material is 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 Multicultural Perspectives. Multicultural Perspectives provide information about particular cultural groups related to the chapter content (e.g., p. 36t). For example, one Multicultural Perspective describes the use of sweat lodges and community steam baths by Native American tribes in order to purify the body (p. 58t). In most Chapter Reviews, a question labeled “Multicultural Perspective” asks students to investigate a particular group’s cultural contributions, which are related to chapter material (e.g., p. 71s, Activities and Projects, item 26). 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. 51s, Activities and Projects, item 27), laboratory investigations (e.g., pp. 52–53s), whole class discussions (e.g., p. 58t, Opening Questions), essay questions (e.g., pp. 50t, 51s, Themes Review, item 20; pp. 70t, 71s, Themes Review, item 23), concept mapping (p. 69s), visual projects (e.g., p. 42t, Teaching Tips, The Cell Factory), research projects (e.g., p. 71s, Activities and Projects, items 27–28), and portfolio (e.g., p. 27t, Effective Reading). 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, supplemental program resources provide additional activities and resources for students (for a description, see pp. 38T–39T).

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. 36t, Application; p. 60t, Application). In addition, some tasks (e.g., p. 26t, Teaching Tips, Sizes of Things; p. 56t, Demonstration; p. 60t, Teaching Tip; p. 65t, Teaching Tips) 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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