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Middle Grades Science Textbooks: A Benchmarks-Based Evaluation

BSCS Middle School Science & Technology: Patterns of Change, Level A. Kendall/Hunt Publishing Company, 1999
Earth Science Life Science Physical Science

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

I. Providing a Sense of Purpose

Conveying unit purpose (Rating = Fair)

Each of the units and chapters begins with a two-page picture, an introductory paragraph, and a list of chapter or section titles. Some of the purposes provided are comprehensible and potentially interesting to students; others are not. The introduction to Patterns of Change (unit 2) shows a cartoon face of Alfred Wegener and a map of the continents at the time of Pangaea (level A, pp. 136-137s). Although the introductory text discusses Wegener, it is unlikely that students will know who he was or what he contributed to the understanding of the Earth. Likewise, the map of Pangaea is likely to be incomprehensible. The introductory text explains that "[we] will explore some of the scientific explanations.and you will learn how people have recognized and used patterns to develop explanations for some of the earth's features" (p. 137s). The statement of purpose is comprehensible and perhaps interesting to students, but students are not asked to think about the purpose.

Similarly Chapter 9: Volcanoes, Earthquakes, and Explantions opens with a photograph of an erupting volcano while its introductory paragraph explains that "[a]s you proceed through this chapter, see whether you can discover people's different ideas about why volcanoes erupt and earthquakes happen" (p. 157s). This statement of purpose is both comprehensible and likely to interest students in the chapter. Lessons in the chapter are consistent with this purpose, and it is returned to at the end of the chapter. In contrast, the introduction to Chapter 10: Connecting the Evidence is not understandable and therefore not likely to interest students. The introductory paragraph explains that "[w]hen scientists cooperate and share their ideas, they often develop explanations that answer many questions at once. As you explore Chapter 10, you will see how certain questions and answers fit together" (p. 195s). This purpose is vague and likely to be unappealing to students. Furthermore, this stated purpose does not convey one of the purposes of the chapter, which seems to be to learn about plate tectonics. The accompanying photograph is actually two photographs (one superimposed on the other), but neither of them clearly helps students better understand the chapter purpose. The chapter purpose is revisited at the end of the chapter.

Conveying lesson/activity purpose (Rating = Fair)

A purpose is presented for many of the student activities. For the most part, the provided purposes will be comprehensible to students. For example, for an activity in which students use clay to model the interactions of the Earth's plates, students read that, "In this investigation, you will be working with teammates to describe what happens at different types of plate boundaries" (p. 208s). For readings, however, the purposes are found in the teacher's notes. Rarely is the purpose of a reading provided in the student text. Students are not asked to think about purposes, and the link between activities and  chapter purpose is never pointed out to them. In several places, the text attempts to orient students to where they are in the chapter by telling them what they have just learned and what is coming next. The text uses some helpful orienting phrases, such as, "In the last investigation, you learned about the earth by listening to other people's observations. In this investigation, you will." (p. 186s), and "During the previous investigation, you probably realized." (p. 197s).

Justifying lesson/activity sequence (Rating = Satisfactory)

At the beginning of each chapter, the Overview section of the Teacher's Edition provides an outline for the chapter. The sections within chapters seem to be ordered in a clear and comprehensible way. However, there is no explicit or detailed rationale for why the chapters within the unit and the sections within the chapters are sequenced the way they are. At the beginning of the textbook, a section in the Teacher's Edition called Program Overview and Goals explains that all of the student activities in the program are sequenced according to an instructional model characterized by the five E's: Engage, Explore, Explain, Elaborate, Evaluate (p. xvii), and all sections within the unit 2 chapters correspond to the five E's (see endnote). However, the sequence of the sections (based on the chapter overviews and the outcomes and indicators of success for each section in the chapter) does not reflect the rationale of the five E's instructional model, which is to take one concept through the cycle of the five E's. Instead, different sections (that is, different E's) focus on different concepts. For example, in chapter 10, the Engage activity has students look for evidence of how the desks in their classroom had been rearranged the night before (p. 196st), one of the Elaborate sections has students investigate convection (pp. 204-206st), and the final Evaluate section has students judge a video or film for the quality of the scientific explanation (pp. 209s, 209-210t).

II. Taking Account of Student Ideas

Attending to prerequisite knowledge and skills (Rating = Poor)

Patterns of Change minimally addresses the prerequisite ideas that are important for the subsequent treatment of the key Earth science ideas. Teachers are not advised about what the prerequisite ideas are or where they are discussed. Only part of one prerequisite idea is addressed minimally. Students could gain a familiarity with some landforms from the few photographs throughout the two chapters (9 and 10). The photographs show landforms, such as a desert (p. 175s), folded rocks (pp. 215s, 216s), and a volcanic mountain (p. 217s). But students' attention is not drawn to the photographs or the diversity of landforms on the Earth, nor are the photographs used to explain how landforms are changed over time. Many important prerequisites are not treated. For example, the difficulties that students may have with proportionality and scale-concepts that would help them understand the slow processes and the long time frames of the Earth (Idea e)-are not addressed.

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

Patterns of Change does not alert teachers to specific misconceptions that are documented in the research literature on student learning. Admittedly, research on students' ideas in the field of Earth science is limited. Even so, this material fails to alert teachers to a well-documented student belief that the Earth is as it always has been or that any changes that have occurred must have been sudden and comprehensive (Freyberg, 1985).

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

Typically, Patterns of Change does not provide questions and tasks designed to probe students' initial ideas about the key Earth science ideas. In only a single case were questions found that could be used for this purpose. At the beginning of chapter 9, just after students watch a video or look at pictures of volcanoes and earthquakes, they are asked: "What do you think might cause earthquakes?  What might cause volcanoes to erupt?" (p. 158s). The Teacher's Edition explains that "[t]his activity provides you with an opportunity to assess the students' prior conceptions about these events" (p. 158t). However, this one instance is insufficient to help teachers probe students' initial ideas about changes to the Earth over time and the processes that could account for them.

Addressing commonly held ideas (Rating = Poor)

Only one attempt is made to address students' commonly held ideas. As students read the historical explanations for volcanoes and earthquakes in a play, the teacher is told: 
[These] explanations may seem inaccurate at first glance. These same theories, however, may match your students' misconceptions about earthquakes and volcanoes.. Respectful treatment of these old ideas may make the students more willing to share their thoughts (and misconceptions) with you. [p. 157at]

However, nowhere in the play, not even in the audience participation questions (embedded within the play), are these ideas challenged or confronted, making this activity unlikely to address the commonly held ideas of students.

III. Engaging Students with Relevant Phenomena

Providing variety of phenomena (Rating = Poor)

Patterns of Change does not provide a sufficient number and variety of phenomena to support the key Earth science ideas. No phenomena are provided for many of the key ideas, such as the surface of the Earth is changing continually (Idea a), the processes that shape the Earth today are similar to the processes that shaped the Earth in the past (Idea c), and slow but continuous processes over very long times can cause significant changes on the Earth's surface (Idea e).

A few phenomena are provided for the idea that several processes contribute to the changing surface of the Earth (Idea b). Unfortunately, very few of these phenomena explain clearly how the processes have changed the Earth. For example, the Teacher's Edition presents several instances of earthquakes and volcanoes, but none of the descriptions explains how the surface of the Earth was changed as a result of such an event (pp. 157a-157ct). Instead, the descriptions of these events tend to focus on the number of deaths and the amount of destruction that occurred as a result. Only the account of the formation of Mount Parícutin includes a brief description of the change to the surface of the Earth: "In 10 months a volcanic cone had grown to more than 300 meters high and 900 meters wide" (p. 157bt).

Some phenomena are provided only in the Teacher's Edition. On occasion, notes in the Teacher's Edition suggest that teachers photocopy the relevant pages as supplemental reading for students (e.g., p. 157at). Most of the phenomena for the idea that some Earth-shaping processes are fast and some are slow (Idea d) is found in the Teacher's Edition. The reading mentions that a San Francisco earthquake lasted 67 seconds, that Mount Parícutin was created in 10 months, and that five large volcanic cones on the island of Hawaii were built up over thousands of years of intermittent lava flows (pp. 157a-157ct).

Very few phenomena target the key ideas about plate tectonics (Ideas g, h). For the idea that plate interactions create landforms and cause geologic events (Idea h), several maps showing features such as the age of rocks, the locations of volcanoes and earthquakes, and features of the ocean floor are presented as evidence for patterns on the Earth (pp. 186−191s.) Later in the next chapter (chapter 10), students read that plate interactions cause earthquakes and volcanoes (pp. 201−204s).

Providing vivid experiences (Rating = Poor)

Only one of the phenomena discussed in the previous criterion could potentially serve as a vicarious experience for students. The Teacher's Edition recommends that students watch several films or videos about volcanoes and earthquakes, which could provide them with a vicarious experience for these two Earth-changing phenomena. However, since no films or videos are provided with this textbook, the quality of this experience is likely uncertain and will depend on other resources available to the teacher.

IV. Developing and Using Scientific Ideas

Introducing terms meaningfully (Rating = Satisfactory)

In most cases, technical terms are introduced with relevant experiences. For example, the term "continental drift" is introduced after students have studied the matching edges of continents and put a "puzzle" together (p. 199s). On the other hand, some of the terms are not well defined or not linked to a relevant experience and hence are incomprehensible.  For example, the terms "folding" and "faults" are introduced, but do not include a good representation to aid understanding (pp. 214-215s). Similarly, the definition of "hot spots" is not clear (p. 217s).          

Overall the number of new technical terms is fewer than typically found in middle grades Earth science textbooks. Notably absent are terms that label land features (such as "loess," "syncline," "dome," "alluvial fan," "arete," "drumlin," "cirques," and "moraine") and terms associated with volcanic eruptions (such as "bombs," "caldera," and "cinders"). However, in some cases, terms that would have facilitated communication about the key Earth science ideas are not presented and some technical terms are used incorrectly. For example, terms such as "diverging" and "converging" were not used to describe how tectonic plates move. Instead, the terms "ridges" and "trenches" (which are landforms, not plate boundaries) are substituted (p. 208t). Using the terms "divergent" and "convergent" for plate boundaries clearly depicts how the plates are moving with respect to one another. Furthermore, not all diverging boundaries have ridges and not all convergent boundaries have trenches. Also, some extraneous terms are included in  chapter 10. For example, the chapter includes a large number of technical terms for rock types, such as "andesite," "granite," "shale," "sandstone," and "quartzite' (pp. 215−216s), that are not linked to relevant experiences, and are not particularly useful for communicating the key Earth science ideas.

Representing ideas effectively (Rating = Poor)

Overall, very few representations are provided to clarify the set of key Earth science ideas. Most of the representations provided are inaccurate, incomprehensible, or not related to the object or event being represented. Some of them are inaccurate because they are overly simplified. For example, the map of the tectonic plates contains major errors, such as having the plate boundary of the Indo-Australian plate end in the middle of the Indian Ocean (p. 202s). Another form of inaccurate representation consists of the use of student-made clay models to demonstrate types of plate boundaries (pp. 208-212s). The students are not asked to consider how their models differ from real plate interactions. Yet another form of inaccurate representation involves using sections of torn newspaper to test, by analogy, Wegener's theory of continental drift (pp. 199−200s).  Although inaccurate representations are difficult to avoid, having students discuss the limitations of representations is an effective way of dealing with inaccuracies. This technique is employed once; students are asked to critique a model of a volcano made from baking soda and vinegar (pp. 157-158a).  It allows them to discuss the inaccuracies of the model-specifically, how it is like and unlike the real thing.

Demonstrating use of knowledge (Rating = Poor)

Patterns of Change does not demonstrate how to use the key Earth science ideas in explanations of phenomena, nor are teachers given suggestions for doing so.

Providing practice (Rating = Poor)

Overall, students have limited opportunities to practice the key Earth science ideas. There are no practice questions or tasks provided for seven of the eight key ideas. The text includes five questions that focus on the idea that the motion of plates creates landforms and causes geologic events (Idea h), but this is inadequate for the set of key ideas. Students are asked how the theory of plate tectonics explains earthquakes, and why the youngest rocks in the ocean are found in the middle (p. 202s). They are also queried as to  how tectonic movement explains the movement of continents and the formation of volcanoes, and how the locations of earthquakes and volcanoes are correlated (p. 204s). None of the questions are novel, and the question set does not increase in complexity. Furthermore, students are not given any feedback.

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

Encouraging students to explain their ideas (Rating = Fair)

Patterns of Changes provides several opportunities for students to express their own thoughts about only some of the key Earth science ideas, mostly those dealing with plate tectonics (Ideas f-h). Questions are provided for students to express and share their ideas in writing, in small groups and in class presentations. For example, chapter 9 begins by asking students what they think might cause volcanoes and earthquakes (p. 158s). However, very few questions throughout chapter 9 focus on the key Earth science ideas. Occasionally, students are asked to clarify or represent their ideas, as for example: "Do you think the continents really could have moved? Explain your answer" (p. 199s, Wrap Up, item 3), and "Draw this arrangement [of the continents 200 million years ago] in your notebook" (p. 198s, Process and Procedure, item 8). In one important instance, the textbook provides feedback to students. After asking them whether they think the continents really could have moved and to explain their answers, students read a nice, three-page description of Wegener's ideas and how he tested them (pp. 199-201s). But this is not typical. Furthermore, there are no suggestions to help teachers provide feedback or to diagnose errors in students' thinking.

Guiding student interpretation and reasoning (Rating = Poor)

There are very few question sets that attempt to guide student thinking about phenomena and readings about the key Earth science ideas. In fact, most of the questions provided focus only on the key ideas dealing with plate tectonics (Ideas f-h). Specifically, after examining maps and being led to see patterns in landforms, students read about Wegener's ideas and observations, and then respond to six questions:
1. List some of the patterns that scientists noticed but did not know how to explain.

2. How does the theory of plate tectonics explain earthquakes.

3. According to the theory of plate tectonics, why are the youngest rocks in the Atlantic Ocean in the middle of the ocean?

[p. 202, Stop & Think]

4. How does the theory of plate tectonics explain why the continents are moving?

5. How does plate tectonic movement explain the formation of volcanoes?

6. Use the theory of plate tectonics to explain the correlations you saw between the locations of volcanoes and earthquakes.

[p. 204, Stop & Think]

While these questions ask students to explain various isolated events in light of the theory of plate tectonics, they are not sequenced in order of increasing complexity to guide students' understanding of the key ideas.

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

Patterns of Change does not typically encourage students to monitor what they have learned. Only once are students invited to check their progress of their understanding. At the end of the unit, the text asks students to look back at the questions and explanations they developed in chapter 9. The text asks: "Which questions can you answer now?  What new questions do you have?" (p. 219s). These questions may engage students in considering how their ideas have changed. It also should be noted that chapter 9 begins with instructions to the teacher to "encourage students to justify their explanations and return to the explanations periodically throughout the unit" (p. 158a). However, throughout the unit, there are no specific suggestions for students to monitor their own ideas.

VI. Assessing Progress

Aligning assessment to goals (Rating = Poor)

Patterns of Change lists a variety of assessment tools to be used at the end of instruction: performance assessment, evaluate activities, the level A test, cumulative portfolios, and projects (Teacher's Resource Book, level A, p. 35). No chapter or unit tests are provided. Unfortunately, most of the items provided in these tools do not focus on the key Earth science ideas. In fact, very few assessment items focus on the key ideas related to plate tectonics (Ideas g, h) and no other key Earth science idea is assessed. The assessment items include questions at the end of chapter 11 that ask students to use the theory of plate tectonics to predict and describe what the Earth will look like if plate tectonics continues for the next 500 million years and what the Earth will look like if plate tectonics stops 100 million years from now (pp. 233-235s). Also, at the end of chapter 10, the Evaluate section in the Teacher's Edition suggests that students could revisit "unanswered questions from Chapter 9" (p. 219t). Although this suggestion does not include a specific page reference for the unanswered questions, some questions from chapter 9 could be used. Candidate questions include: "Why do earthquakes occur in a linear pattern?" "Why do volcanoes and earthquakes occur in some of the same places?" and "Why are the youngest rocks in the same places as many earthquakes?" (p. 191t).  Furthermore, since teachers are advised to have a group, the participation, and thus, assessment of all students is not guaranteed. Overall, only two key Earth science ideas are assessed and the number of questions provided is inadequate.

Testing for understanding (Rating = Poor)

The tasks described under the previous criterion focus on understanding and are novel tasks. Unfortunately, no other questions are provided that require the application of other key Earth science ideas to explain phenomena, identify examples for the general principles, or make predictions.

Using assessment to inform instruction (Rating = Poor)

Patterns of Change lists several opportunities for formative assessment, including the Stop & Think questions in the text, the notebook entries, homework, portfolios, Evaluate activities, and cooperative learning checklists (Teacher's Resource Book, level A, p. 35). However, very few of the questions and tasks in these components focus on the key Earth science ideas. Some tasks are provided that target the ideas related to plate tectonics (Ideas g, h). Although they are not specified for this purpose, these tasks focus on understanding (as opposed to recall) and could be used to diagnose students' remaining difficulties: students use the theory of plate tectonics to explain earthquakes, the formation of volcanoes, the motion of continents, why the youngest rocks in the Atlantic Ocean are in the middle, and how the locations of earthquakes and volcanoes correlate (pp. 202s, 204s)

In addition, students study a topic they choose from a list, describe its connection to plate tectonics, and present it to the class (pp. 212-218s). Of the 14 topics listed, 7 are relevant to the key Earth science ideas:

1. How does the landscape change after a severe earthquake?

6. Why are some rocks on land billions of years old but in the ocean the oldest rocks are only 200 million years old?

7. If most mountains are found on the edges of continents, how can you explain the location of the Ural Mountains?

10. Choose one of the following mountain ranges: the Andes, Himalayas, Cascades, or Appalachians. Explain how that mountain range may have been formed according to the plate tectonic theory.

11. Use the theory of plate tectonics to explain why Mt. St. Helens erupted.

12. According to recent research, the continent of Africa is splitting apart. Describe and show where this is occurring and what the evidence is.

13. Describe what a hot spot is and how scientists can use a hot spot on the ocean floor to indicate the direction of a plate's movement.

[pp. 213-214s]

Furthermore, for questions found in Evaluate sections, the introductory material in unit 2 encourages teachers to ask questions such as: "Why do you think.? What evidence do you have? What do you know about x? How would you explain x?" (level A, p. xviii). Unfortunately, teachers are not reminded of these probing questions in the Evaluate sections throughout the chapters, so this advice may go unheeded. Overall, the material does not include suggestions for teachers about how to interpret students' responses, nor does it include specific suggestions about how to use students' responses to make decisions about instruction.

VII. Enhancing the Science Learning Environment

Providing teacher content support (Some 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. Teacher Background Information notes provide peripherally more extensive (e.g., p. 157at) or sophisticated versions of ideas for selected student text and activity sections. The advanced explanations often do not explicitly alert teachers to how ideas have been simplified for students (e.g., p. 195at), omit connections among concepts (e.g., pp. 195b-195ct), or are not written in an easily comprehensible manner (e.g., p. 195ct). Overall, the Background Information may be used as a selective but not a comprehensive content resource by the teacher.

The material generally provides sufficiently detailed answers to questions in the student text for teachers to understand and interpret various student responses (e.g., p. 162t, item 19). However, there are some limitations to the answers in the teacher's notes, which occasionally contain or may create misconceptions (e.g., p. 207t, Wrap Up, items 2-4) or are absent (e.g., p. 209t, Wrap Up).

The material provides minimal support in recommending resources for improving the teacher's understanding of key ideas. The Teacher's Edition gives a list of "Websites of Interest" with brief, bulleted descriptions and recommendations at the beginning of each chapter (e.g., p. 195dt) and a list of "Educational Technology Resources" (software, CD-ROMs, videos, and laser discs) with recommendations but not descriptions at the beginning of each unit (e.g., p. 139bt). A reference list subdivided by unit without annotations is provided at the end of the Teacher's Edition (pp. 447-450t). Limited descriptions of references in the Teacher's Edition identify topics addressed, but none of the references are explicitly linked to specific text sections or key ideas. In addition, the Teacher's Resource Book has a Background Resources section that includes commentary on science standards documents and general references on learning and assessment strategies.

Encouraging curiosity and questioning (Some support is provided.)

The material provides some suggestions for how to encourage students' questions and guide their search for answers. While the material emphasizes student questions, as in suggesting a topic for which students can create a question to explore (e.g., p. 220t, Further Opportunities for Learning), it gives less attention to guiding students' search for answers. Often, no teacher's notes are provided for how to address the lists of questions generated by students. However, in a few instances, the material does guide students in their search for answers. For example, it provides directions for a think-pair-share strategy for them to develop their explanations (e.g., p. 191s, Connections: Can You Explain the Observations?).

The material provides some suggestions for how to respect and value students' ideas. Teacher's notes sometimes stress that multiple student answers should be acceptable for selected questions (e.g., p. 158at, Class Discussion Questions). The skills "Show respect for others and their ideas" (e.g., p. 159s, Working Cooperatively) and "Treat others politely" (e.g., p. 208s, Working Cooperatively) are stated in multiple places in the student text and teacher's notes as new cooperative group skills. However, other than stating the skills, the material does not usually provide students with any further support in how to enact the skills within their cooperative groups. For example, the rationale for the skill "Show respect for others and their ideas" is stated only once in the teacher's notes (p. 138t, Cooperative Learning Overview), and single examples of what this skill would look like in cooperative group work are given only in the student text (pp. 138-139s, Cooperative Learning Overview) and teacher's notes (p. 158bt, Getting Started).

The material provides many suggestions for how to raise such questions 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?" for explanations of earthquakes and volcanoes (e.g., p. 184s, Reading: Evaluating Explanations). However, the material does not routinely encourage students to pose such questions themselves.

The material provides some suggestions for how to avoid dogmatism. For example, the student text portrays the nature of science as a human enterprise in which students may participate (e.g., pp. 186-191s, Investigation: Patterns on the Earth). In addition, the material includes the work of particular, practicing scientists (e.g., pp. 162-183s, Volcanoes and Earthquakes: Explanations from the Past) and describes changes over time in scientific thinking about earthquakes and volcanoes (pp. 184-186s, Reading: Evaluating Explanations).

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, some sense of desirable student-student interactions may be gained from procedural directions and descriptions of student roles and social skills in cooperative group activities (e.g., pp. 197-199s, Working Cooperatively, Investigation: Continents on the Move).

Supporting all students (Some support is provided.)

The material generally avoids stereotypes or language that might be offensive to a particular group. For example, the text includes a diverse cultural mix of students and adults in photographs (e.g., pp. 68s, 115s, 133s) and illustrations of diverse cartoon animal characters who routinely share their thinking in figures throughout the material (e.g., pp. 122s, 147s, 204s). The cartoon characters are representative of the four different learning styles of students and particular scientists (Europeans only). In some ways, however, the text may contribute to stereotypes and language that might be offensive. Scientists are often shown in stark black and white drawings that students may find odd or unreal (e.g., p. 167s). The text gives some historical reviews of scientific thinking that represent primitive thinking of Asian groups and current, sophisticated thinking of European groups with emphasis on male scientists (pp. 162-182s, Volcanoes and Earthquakes: Explanations from the Past). Time periods are sometimes represented as B.C. and A.D., which may be offensive to particular religious groups (pp. 162-181s, Volcanoes and Earthquakes: Explanations from the Past). While the teacher's notes explain the meaning of these conventions (p. 159t, Getting Started), they might also note other ways in which different cultural groups, especially those in the play, have recorded time.

The material provides some illustrations of the contributions of women and minorities to science and as role models. The illustrations sometimes occur in the main text (e.g., pp. 170-176s, Act II: A New Invention). They are also presented in sidebars that are interesting and informative, but may not be seen by students as central to the material (e.g., p. 192s, Sidelight on History). Children doing science in the video materials as well as cartoon characters of European scientists in the text are intended as role models for students. It is unclear, however, if students will relate to the cartoon animal figures, and the figures' dialogues may appear superfluous to the main content of the text (e.g., p. 204s).

The material suggests multiple formats for students to express their ideas during instruction, including individual investigations and notebook writing (e.g., pp. 212-213s, Investigation: Plate Tectonics Research), cooperative group activities and lab investigations (e.g., pp. 197-199s, Investigation: Continents on the Move), play acting (e.g., pp. 158-183s, Investigation: And Along the Way They Met.), and whole class discussions (e.g., p. 158s, Connections: Can You Imagine?). Introductory teacher's notes suggest using a wide variety of classroom activities for assessment, including in-class discussion, notebook entries, portfolios, and Evaluate activities (Teacher's Resource Book, p. 35). 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. There is only one instance of modifying an activity for more advanced students (p. 187t, Process and Procedure). However, the Teacher's Edition and Teacher's Resource Book provide some additional activities and resources for students. Within each chapter, the Teacher's Edition provides Further Opportunities for Learning in which students may further study a related interest (e.g., p. 220t), sometimes using chapter and unit resources that include websites (e.g., pp. 157c-157dt) and educational technology resources (software, CD-ROMs, videos, and laser discs [e.g., p. 139bt]). The Teacher's Resource Book includes a few extension activities similar in complexity to those in the student text (e.g., pp. 188-190).

The material provides a few strategies to validate students' relevant personal and social experiences with scientific ideas. A few text sections include brief references to specific personal experiences that students may have had that relate to the presented scientific concepts (e.g., p. 142s, Investigation: How Do You Know?). In addition, a few tasks ask students about particular personal experiences they may have had, or suggest specific experiences they could have. For example, in the beginning of chapter 9 (about explanations of volcanoes and earthquakes), teacher's notes suggest asking "students to share their ideas about, and perhaps experiences with, earthquakes and volcanoes" (p. 157t, Strategies). However, the material rarely encourages students to contribute relevant experiences of their own choice to the science classroom, and sometimes does not adequately link the specified personal experiences to the scientific ideas being studied (e.g., p. 158s, Connections: Can You Imagine?, item 2). Overall, support is brief and localized.


Diversity and Limits describes its use of the five E's instructional model as follows: "Each chapter goes through a cycle of activities, and each activity exemplifies one of the "E" words. First the students are engaged by an event or question related to the concept that the teacher plans to introduce. Then the students participate in one or more activities to explore the concept. This exploration provides students with a common set of experiences from which they can initiate the development of their understanding of the concept. In the explain phase, the teacher clarifies the concept and defines relevant vocabulary terms. Next, the students elaborate and build on their understanding of the concept by applying it to new situations. Finally, the students complete an activity that will help them and the teacher evaluate their understanding of the concept" (level B, p. xvii).