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AAAS  :: Project 2061  :: Textbook Evaluations

Middle Grades Science Textbooks: A Benchmarks-Based Evaluation

Glencoe Earth Science, Life Science, and Physical Science. Glencoe/McGraw-Hill, 1997
Earth Science Life Science Physical Science

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

I. Providing a Sense of Purpose

Conveying unit purpose (Rating = Poor)

Unit and chapters purposes, generally appear in the opening sections of the units and chapters in the student text. A typical unit opening section includes a large photograph, an introductory paragraph, and a Science Journal activity. Customarily, the introductory paragraph includes a vague statement of the unit's purpose. For example, the unit 2 paragraph states that, "As you study this unit, you'll learn about the many processes that change the shape of our world" (p. 117s). However, because it is unclear what those processes are, it is unlikely that this purpose will be comprehensible or interesting to students. On the other hand, the unit 3 opening statement explains that students should "[r]ead on to learn more about volcanoes, earthquakes, and plate tectonics, and how these processes impact life on the surface of the planet" (p. 233s). Because students are not likely to be familiar with plate tectonics, they may find this statement to be uninteresting.  However, they probably will be interested in finding out more about earthquakes and volcanoes.

A typical chapter opening section includes a photograph, an introductory paragraph, and an Explore activity. Like unit purposes, chapter purposes are included in the introductory paragraph. However, they are usually found in the Teacher Wraparound Edition, rather than the student text. For example, the purpose for Chapter 7: Erosional Forces is found in the Teacher Wraparound Edition, which asks the teacher to "[i]nform students that this chapter will discuss more about agents of erosion and deposition" (p. 171t). Furthermore, some chapters (e.g., Chapter 8: Water Erosion and Deposition and Chapter 11: Plate Tectonics) lack a statement of purpose.

Throughout the material, the chapter purposes seldom consist of statements likely to engage the interest of students.

The lessons in each chapter are consistent with the stated purpose. However, students are not asked to think about the stated purpose; nor are the purposes returned to at the end of each chapter, as is also true of each unit.

Conveying lesson/activity purpose (Rating = Poor)

To convey purposes for readings and activities, each section of text begins with two or three objectives. As these objectives are filled with technical terminology (such as "till," "outwash," "slumps," "creep," "chemical weathering," "deflation," "continental drift," and "seafloor spreading"), students will have difficulty understanding the purposes.

Purposes are provided for the activities in the student textbook too, such as the MiniLAB activities. These purposes are presented in the form of questions that also serve as the titles of the activities. Some of them are likely to be incomprehensible to students-as, for example, "How do convection currents form?" (p. 310s) and "What causes mass movements?" (p. 176s). The larger investigations typically do not provide a clear and comprehensible purpose for the investigation. The text does not encourage students to think about the purpose, show how the activity is related to the purpose of the unit or the chapter, or stimulate students to think about what they have learned so far and what they need to learn next.

Justifying lesson/activity sequence (Rating = Poor)

No rationale is provided for why the chapters or the activities in them are sequenced as they are. Furthermore, the sequence used has flaws. The sequence begins with the changes that occur on the Earth's surface (Chapter 6: Weathering and Soil, Chapter 7: Erosional Forces, and Chapter 8: Water Erosion and Deposition); then it presents the Earth's internal processes (Chapter 9: Earthquakes and Chapter 10: Volcanoes); and, finally, it sets forth the underlying reason for these internal processes in Chapter 11: Plate Tectonics. One of the main problems with this topic sequence is that the material refers constantly to the theory of plate tectonics in chapters 9 and 10, long before it is presented in chapter 11.

II. Taking Account of Student Ideas

Attending to prerequisite knowledge and skills (Rating = Poor)

Three prerequisite ideas are addressed in this material: the variety of landforms, gravity, and the expansion of water. Although section 5.1 (pp. 120-125s) introduces a number of landforms, vivid photographs and pictures of landforms that would help students develop familiarity with a variety of landforms are scattered throughout the text. Gravity is explained first on page 20s and redefined later in relation to its role in erosion and deposition (p. 173s). A small section in Chapter 6: Weathering and Soil explains how the unique characteristic of water (expanding as it freezes) contributes to the mechanical breakdown of rocks. Although the text does not explain that water expands as it freezes, the caption on the accompanying illustration does (p. 150s, Figure 6-3).

The material does not treat important prerequisites, such as the following:

  • Knowing that when tiny fractions are multiplied by very large numbers, very large numbers can result (so that students can appreciate that small but continual processes can make significant changes over long time periods).

  • Knowing that matter is conserved; although matter may move from one place to another or change form, it does not merely appear or disappear (so that students can appreciate that erosion from one place results in deposition at another).

  • Knowing that models are useful for thinking about processes that happen too slowly or too quickly.

Although this material has students make models of Earth science processes (for example, using wooden blocks to demonstrate fault-block mountains [page 124t] and using gravel and water to demonstrate erosion [page 171s]), students are not told that models are used in science for thinking about processes that happen too slowly or too quickly or are too large or too small to witness firsthand.

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

Although the Teacher Wraparound Edition includesa section called Revealing Preconceptions, this section does not contain helpful information about students' naive conceptions or misconceptions. Admittedly, the 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-namely, that the Earth is as it always has been (Freyberg, 1985).

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

Identifying students' ideas about a topic is not a stated feature of this material. However, each section in a chapter begins with a Bellringer activity (including a transparency and work sheets for students) that could be used by teachers to find out what students know about the subject before instruction begins. The Bellringer segment is not identified as serving this purpose. Although some of the Bellringer activities are not valid for the key Earth science ideas, most of the Bellringer questions are likely to be comprehensible to students because they use nontechnical language and real-life settings.

Occasionally, students are asked to give reasons for their ideas or to explain what they think. For example, before the section on weathering in Chapter 6: Weathering and Soil, a Bellringer activity has students examine a photograph of an old stone statue. They are asked: "You probably would know without being told that this statue has been around for hundreds of years. How do you know?" (p. 146Ct, Section Focus Transparency 24, L1).

Addressing commonly held ideas (Rating = Poor)

Students are not invited to make predictions and to compare their predictions to what happens. They are not prompted to contrast their own ideas with scientifically correct ideas and to resolve differences between them. Furthermore, the material makes no attempt to guide teachers on taking their students' ideas into account.

III. Engaging Students with Relevant Phenomena

Providing variety of phenomena (Rating = Poor)

A wide variety of phenomena are provided for most of the key Earth science ideas. However, most of them are not linked to real Earth features. For example, for the idea that several processes contribute to the changing surface of the Earth, Chapter 6: Weathering and Soil opens with a photograph of the statues on Easter Island (pp. 146-147s). The text explains that, probably, these mysterious statues will be worn away through processes of weathering, but it does not relate this phenomenon to how the Earth's surface undergoes the same weathering processes. Similarly, students are to investigate the chemical weathering of chalk (pp. 152-153s) and steel wool (p. 154s), but neither activity provides a link (a question or an explanation) that focuses their attention on the fact that these chemical processes break down features on the Earth's surface as well.

At other times, opportunities are missed to develop real-world events and land features into phenomena. For example, Chapter 11: Plate Tectonics has many examples of land features that have resulted from the movement of tectonic plates, such as the Mid-Atlantic Ridge and the Great Rift Valley in eastern Africa (pp. 305s, 312s), the Himalayan and Appalachian mountains (p. 312s), Japan (as a volcanic island arc, p. 308s), and the San Andreas Fault (pp. 309s, 310s, 313s). All are mentioned in the text as one-sentence examples of landforms resulting from plate motions. None are explained with sufficient detail to enable students to comprehend why they provide evidence for plate motion. Also, it is likely that many students have not heard of the Great Rift Valley.

Providing vivid experiences (Rating = Poor)

There are no firsthand or vicarious experiences for this set of key Earth science ideas.

IV. Developing and Using Scientific Ideas

Introducing terms meaningfully (Rating = Poor)

This textbook presents far more terms, particularly technical terms, than are needed for effective communication about the key Earth science ideas. In a few cases, terms are used several chapters before they are introduced and defined. Such terms include "plates," "plate tectonics," and "continental shelf." Also, some sidebars have students explore complex terms unnecessarily; for example, students are told to find out what the "Curie point" is (p. 301s).

The material does not provide experiences with phenomena and then develop definitions of the terms needed to interpret those experiences. Although many terms are linked to diagrams, typically the depictions are of such poor quality that they do not clarify the meaning of the designated item. Also, central terms are introduced with only a one-sentence definition; the first time that "erosion" is mentioned in the text, for example, it is described only as "the movement of weathered material" (p. 101s). No examples, models, or illustrations are provided. The next time students encounter the term "erosion," no reference is made to the original definition. Furthermore, the text assumes that students understand what "erosion" means, as is evident in such statements as, "Erosional forces constantly change the surface of Earth, making changes in our landscape" (p. 171s). Another important term, "plate" (as in "tectonic plate"), is defined as a broken section of the Earth's crust and upper mantle (p. 304s). However, the associated diagram (Figure 11-8, showing crust, lithosphere, and asthenosphere) does not show what a plate encompasses (p. 304s).

Representing ideas effectively (Rating = Poor)

Most of the representations for the key Earth science ideas have questionable comprehensibility. For example, for the idea that the Earth is changing constantly, a mountain range diagram (p. 148s, Figure 6-1) probably is intended to look like three views of the same mountain worn down over time. Unfortunately, the legend does not explain that it is showing three superimposed views of the same mountain. For the idea that several processes contribute to changing the Earth's surface, the material offers a diagram of a retreating glacier and the land features it has created, but it is unclear what distinguishes a drumlin from an erratic from a till (p. 184s, Figure 7-13). Also, the diagram that attempts to show how soil creeps in freeze-thaw cycles is confusing (p. 174s, Figure 7-4). In addition, Figure 6-3 (p. 150s), which attempts to show what happens to rock in freeze-thaw cycles, does not make clear how the water gets into the rock in the first place; neither the figure legend nor the accompanying text explains that the figure shows the "last" cycle to occur before the rock cracks. For the idea that fossils and rock layers in now widely separated continents are evidence of an earlier, single, and vast continent, a diagram shows where similar fossils have been found on different continents (pp. 294-295s). From the scale of the fossils, though, it is difficult to know where they were found; for example, one Glossopteris fossil is shown to span India and the Himalayas. For the idea that landforms result from the movement of plates, the diagram of fault-block mountains (p. 312s, Figure 11-13) is completely incomprehensible.

On the other hand, some representations are accurate, comprehensible, and linked to the real thing. One such example consists of an activity that has students model different ways that natural  processes move sediments (p. 171st).

Demonstrating use of knowledge (Rating = Poor)

The material contains only two instances of attempts to show students how the key Earth science ideas can be used to explain phenomena. One instance occurs after students have read about plate tectonics and how the interactions of plates can create landforms and cause geologic events. Students then read a section on the effects of plate tectonics. It contains a few examples of the effects of plate interactions (the Great Rift Valley, the Appalachian and Himalayan mountains, the San Andreas Fault [pp. 311-313s]) plus a brief explanation using the key idea that plate interactions create landforms and cause geologic events. However, the explanations provided are neither step-by-step (to help students follow them), nor labeled as a demonstration (so that students' attention is drawn to them), and no running commentary is provided (so that students can learn how to use the key ideas to explain other relevant phenomena). The explanation of the formation of the Great Rift Valley leaves out too many steps for students to be able to understand it: "As the plates move, they interact. The interaction of plates produces forces that build mountains, rift ocean basins, and cause volcanoes and earthquakes" (p. 311s).

In the second instance, the text does well in using the idea that erosion occurs continually to inform decisions about where to build houses (pp. 178-179s). The section, entitled Issue: Developing Land Prone to Erosion, begins:

Some people like to live in houses and apartments on the sides of hills and mountains. Realtors say that people want to live in these places for the good view. But when you consider gravity as an agent of erosion, do you think steep slopes are safe places to live?

Then, two points of view are presented: Steep Slopes Can Be Made Safe (through carefully planted vegetation) and Building on Steep Slopes Is Dangerous (erosion occurs naturally, and some steep slopes have weak sediment layers underneath, making them prone to slumps). However, the text does not tell students that it is modeling the use of a key idea, nor does it provide appropriate running commentary (for example, note how both sides of the issue have been considered, and the science ideas that support each side have been identified).

Providing practice (Rating = Poor)

There are practice tasks for only two of the key Earth science ideas. Several practice tasks (including some novel tasks) are given for the idea that several processes change the Earth. However, as each of these Earth-changing processes is practiced separately from the others, students never get to practice the idea that several processes contribute to changing the Earth's shape. Most of these tasks involve practicing the use of vocabulary and focusing on linking the feature to the process, instead of understanding the process.

For the idea that fossils and matching coastlines are evidence of an ancient, vast, and single continent, the textbook suggests some practice tasks, such as writing a letter in defense of Wegener's idea of continental drift (p. 297s). For the idea that the Earth is changing continuously, there are only implicit practice questions, such as calculating how far apart North America and Africa will be in 200 million years (p. 301s). Practice questions are omitted for other important and difficult Earth science ideas such as that some Earth-changing processes are fast while others are slow, and that slow but continuous processes can eventually result in a large change to the surface of the Earth.

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

Encouraging students to explain their ideas (Rating = Poor)

A few features routinely elicit students' ideas: Science Journal, Bellringer, and Flex Your Brain. Unfortunately, these features are not focused generally on the key Earth science ideas. Bellringer appears at the beginning of each section and attempts to draw out students' ideas before instruction. Flex Your Brain usually appears in the Assess segment of the Teacher Wraparound Edition for each section of a chapter. As there is no guidance for the teacher and only a general topic is given to the students, it is uncertain whether the Flex Your Brain activities concentrate on the key Earth science ideas. Instead, they seem to focus on certain phenomena, such as, slope (p. 175t), glaciation (p. 185t), sand dunes (p. 194t), shorelines (p. 224t), and earthquakes (p. 239t).

Other opportunities for students to express their ideas, such as Science Journal, appear less regularly throughout the chapters. Science Journal gives students a chance to write their thoughts about particular topics, but there are no further directions to teachers about how to use the Science Journal feature in specific contexts, such as asking students what it would be like to go far back in time to exactly the same spot (p. 117s) or why the Himalayan mountains are growing still (p. 123s), and drawing a series of pictures that show how mountains change shape over time (p. 150t). Other features, such as Visual Learning and Inquiry Questions (in the Teacher Wraparound Edition), and Section Wrap-ups (in both the teacher and student books) seem to focus on the recall of information in the text. For example, students are asked to "[d]efine erosion and name the agents that cause it" (p. 177s) and answer the question, "How did Wegener use climate clues to support his hypothesis about continental drift?" (p. 297s). Rarely are they asked to clarify, justify, or represent their own ideas in Science Journal or other features.

Guiding student interpretation and reasoning (Rating = Poor)

In most cases, an activity is followed by questions that help students make sense of the activity. However, often these questions do not ask students to relate the activity or the experience to an actual earth phenomenon or event. For example, students are to rub several kinds of rocks against a metal file and compare the amounts of particles broken off from each rock (p. 147s), but they are asked only which types of rocks break apart most easily and to describe each rock. No questions are provided to help them think about how this activity mimics a natural process that changes the shapes of rocks. Furthermore, they are not asked to relate what they observe to their own ideas or to correct scientific ideas. The questions that follow the reading section ask students only to recall what they have read-as, for example, "Compare and contrast abrasion and deflation. How do they affect the surface of Earth?" (p. 195s) and "What happens to plates at a transform fault boundary?" (p. 313s).

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

The Flex Your Brain feature requires students to write what they know about a topic, research the topic further, write about what they found, and compare their new knowledge to their original statement. It is possible that students will use this feature to monitor their learning and ideas with respect to the key Earth science ideas. However, the topics given to students are general and vague-for example, slope (p. 175t), glaciation (p. 185t), sand dunes (p. 194t), shorelines (p. 224t), and earthquakes (p. 239t). It is uncertain what students will investigate. Neither the text nor the teacher's instructions guide students toward exploring the key Earth science ideas. These activities could be more helpful if students were asked more directed questions, especially questions involving change over time, a concept that most middle grades students have difficulty accepting (Freyberg, 1985 ).

VI. Assessing Progress

Aligning assessment to goals (Rating = Poor)

The key Earth science ideas examined here are not covered adequately by assessment items. Most of the ideas are not addressed at all; for others, there are insufficient assessment items. For the end-of-instruction assessment, the material provides-in two separate resource books (Chapter Review and Assessment: Chapter and Unit Tests)-a two-page review and a four-page test for each chapter and a test for each unit. These components of chapters 7 to 11 and units 2 and 3 have been evaluated.  

Most relevant assessment items target the idea that several processes contribute to changing the Earth's surface. However, the assessments typically focus on the details of specific processes and not on the generalization that the Earth's surface is changed by several processes. Students are asked to determine "which are steeper, younger mountains or older mountains" and to explain their answers (Assessment: Chapter and Unit Tests, p. 43, Chapter 7 Test). They are to explain "why some shorelines are rocky and others have sandy beaches" (Assessment: Chapter and Unit Tests, p. 47, Chapter 8 Test), and choose the terms that complete these statements best:

A _____ is formed when water empties into a lake, gulf, or ocean. [Assessment: Chapter and Unit Tests, p. 45, Chapter 8 Test]

As Earth's plates pull apart at some boundaries, they collide at others, forming _____. [Assessment: Chapter and Unit Tests, p. 67, Chapter 11 Test]

Where plates move past one another, _____ occur. [Assessment: Chapter and Unit Tests, p. 68, Chapter 11 Test]

Seafloor spreading occurs because _____. [Assessment: Chapter and Unit Tests, p. 68, Chapter 11 Test]

For the idea that evidence suggests that today's continents are separated parts of what was a single continent long ago, the material asks students to choose the phrases that complete these statements best: "Fossils of the warm-water animal Archaeocyatha, found in Cambrian rocks of East Antarctica, suggest that _____" and "The presence of the same _____ on several continents supports the idea of continental drift" (Assessment: Chapter and Unit Tests, p. 67, Chapter 11 Test). Further, students are asked to explain why Wegener believed that "all of the continents had once been joined" and why an ocean fish fossil found on two different continents would not be good evidence of continental drift (Assessment: Chapter and Unit Tests, pp. 69-70, Chapter 11 Test).

Several questions relate to the idea that landforms and major geologic events result from plate motions.  Students are asked whether the statement, "There is no relationship between plate tectonics and volcanoes" is true and why volcanoes, "form at plate boundaries and hot spots" (Assessment: Chapter and Unit Tests, pp. 64, 66, Chapter 10 Test). They are also asked why there are many earthquakes in the Himalayas, and "how research from the Glomar Challenger helped scientists support the theory of seafloor spreading" (Assessment: Chapter and Unit Tests, p. 70, Chapter 11 Test). In addition, students are to choose the terms that complete these statements best:

As Earth's plates pull apart at some boundaries, they collide at others, forming _____.

Continental drift occurs because of _____.

Where plates move past one another, _____ occur.

Seafloor spreading occurs because _____.
[Assessment: Chapter and Unit Tests, pp. 67-68, Chapter 11 Test]

No other tasks are provided to assess students on the ideas examined here. This material does include many assessment tasks that evaluate students on their familiarity with relevant vocabulary. For example, students are to match columns of terms to their definitions, choose the terms that complete statements best (for example, "The dropping of sediments by any agent of erosion is called _____" [Assessment: Chapter and Unit Tests, p. 49, Unit 2 Test]), explain the difference between a convergent and a divergent plate boundary (Assessment: Chapter and Unit Tests, p. 67, Chapter 11 Test), and unscramble letters to reveal relevant terms. These assessment items are judged to be unaligned with the key ideas because students do not have to know any of the key ideas in order to answer them correctly.

Also, many of the assessment questions focus on the mechanisms of the processes, rather than on their impact on the Earth's surface; therefore, they are not aligned with the idea that several processes contribute to changes on the Earth's surface. For example, students compare and contrast slump and creep (Assessment: Chapter and Unit Tests, p. 42, Chapter 7 Test) or choose the phrase that completes this statement correctly: "Ice wedging is caused by _____" (Assessment: Chapter and Unit Tests, p. 48, Unit 2 Test).  

Testing for understanding (Rating = Poor)

Of the relevant assessment items described under the previous criterion, four require the application of key ideas. Students are asked which are steeper, younger mountains or older mountains, and to explain their answers. They are to explain why some shorelines are rocky and others have sandy beaches, and why an ocean fish fossil found on two different continents would not be good evidence of continental drift. Lastly, they are to explain why there are many earthquakes in the Himalayas. None of these questions is a novel task; therefore, students’ ability to transfer the ideas learned to novel contexts is not assessed. These items are clearly insufficient to assess students’ understanding of the key Earth science ideas.

Using assessment to inform instruction (Rating = Poor)

The introduction in the Teacher Wraparound Edition, states that “Glencoe Earth Science contains numerous strategies and formative checkpoints for evaluating student progress toward mastery of science concepts” (p. 45T). Section Wrap-ups, Mini-Quizzes, and Chapter Reviews in the student text are identified as components that can help teachers determine whether any substantial reteaching is needed.

However, the material does not include suggestions about how to probe beyond students’ initial responses or how to modify instruction according to their responses. Most significantly, it does not include sufficient quality questions that can help even an informed teacher to diagnose a student’s remaining difficulties with respect to the ideas examined.

While many of the questions can be answered by copying from the text, some questions are aligned with the key ideas. Students are asked to explain how glaciers cause erosion and to imagine finding a large rock that matches rocks normally found in Canada and account for how it got there (p. 187s); compare and contrast weathering and erosion and discuss the causes and effects of slumping (p. 198s); explain why there is no sand on many of the world’s shorelines (p. 226s); and why shorelines are changing constantly (p. 228s). Students are to describe what the Pacific ring of fire is (p. 273s) and how volcanoes and earthquakes are related (p. 290s). They are to compare and contrast continental drift and plate tectonics and divergent, convergent, and transform fault boundaries (p. 318s). They are to explain how island arcs form and why there are few volcanoes in the Himalayas but many earthquakes (p. 318s). Lastly, they are asked to discuss why a fossil of an ocean fish found on two different continents would not be good evidence of continental drift (p. 318s).

VII. Enhancing the Science Learning Environment

Providing teacher content support (Minimal support is provided.)

The material provides minimal support in alerting teachers to how ideas have been simplified for students to comprehend and what the more sophisticated versions are. Content background notes in the Teacher Wraparound Edition usually summarize the student text (e.g., p. 188t), offer tidbits of questionable relevance (e.g., p. 266t), or present additional terms (e.g., p. 276t). Overall, the teacher content support is brief, localized, and fragmented.

The material rarely provides sufficiently detailed answers to questions in the student text for teachers to understand and interpret various student responses. Most answers are brief and require further explanation (for example, "Students should have similar results" [p. 193t, Analyze and Apply, item 1]); often, they emphasize a "right-answer" approach (for example, "The most logical sequence of events is c, b, a, and d" [p. 195t, Skill Builder]).

The material provides minimal support in recommending resources for improving teachers' understanding of key ideas. While the material lists references that could help teachers improve their understanding of key ideas (e.g., "Lasca, Norman P. 'Build Me a River,' Earth, Jan. 1991, pp. 59-65" [p. 61T]), the lists lack annotations about what kinds of information the references provide or how they may be helpful.

Encouraging curiosity and questioning (Minimal support is provided.)

The material provides a few suggestions for how to encourage students' questions and guide their search for answers. A generic Flex Your Brain work sheet encourages students to pose a question about a topic studied and gives them three broad guiding questions to use in their search for answers: "What do I already know?" and "How can I find out?" and "What do I know now [after exploration]?" (p. 29T). Teacher's notes suggest topics students can explore (e.g., "plate tectonics" [p. 312t]) but provide no other guidance.

The material provides a few suggestions for how to respect and value students' ideas. Introductory teacher's notes about cooperative learning state that students will "recognize.the strengths of others' [perspectives]," be presented with "the idea that there is no one, 'ready-made' answer" (p. 24T), and "respect other people and their ideas" (p. 46T). Introductory teacher's notes also state that student responses may vary in concept mapping tasks. Teachers are thus instructed to "[l]ook for the conceptual strength of student responses, not absolute accuracy" (p. 30T). In addition, Design Your Own Experiment activities are structured to be open-ended, allowing students to pursue a laboratory task in various ways. However, teacher's notes often give specific expected outcomes for these activities, which may limit their intended open-ended nature (e.g., pp. 302-303t).

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. 297t, Section Wrap-up, item 2; Critical Thinking/Problem Solving resource book, p. 17, item 2).

The material provides a few suggestions for how to avoid dogmatism. Introductory teacher's notes state that "[s]cience is not just a collection of facts for students to memorize" but is "a process of applying those observations and intuitions to situations and problems, formulating hypotheses, and drawing conclusions" (p. 25T). The first chapter portrays the nature of science as a human enterprise that proceeds by trial and error and uses many skills familiar to students (pp. 4-29st). Later, the material explains changes over time in scientific thinking leading to the theory of plate tectonics. But most of the text is generally presented in a static, authoritative manner with little reference to the work of particular practicing scientists, and single specific responses are expected 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 laboratories and cooperative group activities (e.g., pp. 192-193st, Activity 7-2; p. 237t, Activity, Interpersonal; Cooperative Learning in the Science Classroom resource book, pp. 17-18).

Supporting all students (Some support is provided.)

The material generally avoids stereotypes or language that might be offensive to a particular group. For example, several photographs include a diverse cultural mix of students and adults (e.g., pp. 249s, 270s, 316s).

The material provides some illustrations of the contributions of women and minorities to science and as role models. While the introductory teacher's notes state that "[n]o single culture has a monopoly on the development of scientific knowledge" (p. 38T), most of the contributions of women and minorities appear in separate sections entitled People and Science. For example, Chapter 11: Plate Tectonics includes an on-the-job interview with a woman geologist who is working on the National Aeronautics and Space Administration's Magellan project (p. 316st). In addition, Cultural Diversity teacher notes highlight specific cultural information related to chapter topics (e.g., p. 121t). A separate Multicultural Connections resource book contains short readings and questions about individual scientists or groups addressing text-related issues in many parts of the world (e.g., Multicultural Connections, pp. 13-14). All of these sections highlighting cultural contributions are interesting and informative, but may not be seen by students as central to the material because they are presented in sidebars, supplemental materials, and teacher's notes.

The material suggests multiple formats for students to express their ideas during instruction, including individual investigations and journal writing (e.g., p. 171s, Explore Activity), cooperative group activities (e.g., p. 311t, Activity), laboratory investigations (e.g., pp. 302-303st, Activity 11-1), whole class discussions (e.g., p. 316t, Teaching Strategies), essay questions (e.g., pp. 318s, 319t, item 20), and concept mapping (e.g., p. 240st, Skill Builder). In addition, multiple formats are provided for assessment, including oral discussion (e.g., p. 297t, Assessment), essay (e.g., Assessment: Chapter and Unit Tests, p. 69, item 3), performance (e.g., p. 303t, Assessment), and portfolio (e.g., p. 227t, Assessment Portfolio). However, the material does not usually provide a variety of alternatives for the same task (except in rare instances for special needs students).

The material does not routinely include specific suggestions about how teachers can modify activities for students with special needs. However, the Teacher Wraparound Edition and supplemental Program Resources (including reinforcement and enrichment work sheets, a study guide, and activities with transparencies) provide additional activities and resources for students of specific ability levels. At the beginning of each chapter, teacher's notes link the various chapter activities to different learning styles (e.g., p. 200t, Learning Styles). Several of the visual-spatial activities are also coded LEP for students with limited English proficiency (e.g., p. 296t, Visual Learning). For Spanish speakers, there are English/Spanish audiocassettes, which summarize the student text in both languages, and a Spanish Resources book, which translates key ideas and activities for each chapter. Teacher's notes about Meeting Individual Needs at the beginning of the Teacher Wraparound Edition highlight the importance of providing "all students with a variety of ways to learn, apply, and be assessed on the concepts" (p. 39T). However, the placement of supplemental resources in individual booklets separate from the main text may discourage their use, and the special needs codes within chapters may discourage teachers from using those activities with all students. Also, a few of the activities suggested for students with special needs are not well suited for the intended students (e.g., p. 192t, Inclusion Strategies).

The material provides some strategies to validate students' relevant personal and social experiences with scientific ideas. Many text sections begin with a brief reference to a specific personal experience students may have had that relates to the presented scientific concepts (e.g., p. 236s). In addition, some tasks ask students about particular personal experiences they may have had or suggest specific experiences they could have. For example, Community Connection teacher notes suggest that students photograph locations in their local community where water erosion has taken place (p. 207t). 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. 196s, Science Journal). Overall, support is brief and localized.