For the idea that several processes contribute to the changing surface of the Earth (Idea b) the text presents a few phenomena. For example, it describes how moving water has eroded Niagara Falls (Level Green, pp. 474-477s), the eruption of Mount Paricutin (Level Red, p. 375s), and how the island of Surtsey formed (Level Red, p. 376s). The text also includes several descriptions of processes that shape the surface of the Earth, but typically these descriptions either do not include phenomena or do not discuss how the Earth has changed as a result of the processes.

For the idea that some Earth-changing processes are fast and some are slow (Idea d), the text presents a map that shows the changing location of Niagara Falls over the last 300 years (Level Green, p. 476s), describes a landslide in Canada moved at tremendous speed (Level Green, p. 488s), and notes how the island of Surtsey took three-and-a-half years to form from volcanic eruptions (Level Red, p. 376s).

There are no phenomena to support the idea that slow but continuous processes over time can create major changes to the surface of the Earth (Idea e). Although two changes that occur over long periods of time are referred to (namely, the formation of the Grand Canyon [Level Green, p. 472t] and the spreading of Great Rift Valley of Africa over the next few million years [Level Green, p. 464t]), the fact that small changes accumulate into visible changes over long time frames is not explained.

For the idea that matching coastlines, rocks, and fossils suggest that today's continents are separated parts of an ancient single vast continent (Idea f), the phenomena provided are not explained well enough for their significance to be appreciated (and hence for them to support the key idea). The text mentions all three of these pieces of evidence-matching coastlines, rocks, and fossils-as well as coal deposits in Antarctica, in the context of a mock debate (Level Green, pp. 460-461s). But it does not explain why such of evidence requires explanation. For example, to fully appreciate the significance of the matching fossil evidence, students need to know that these continents now have quite different climates (because they are on different latitudes), that fossils typically are found where organisms once lived, and that organisms usually only thrive in particular climates. Thus, if fossils of the same organism are found in widely separated latitudes, then it is likely that these locations formerly had the same climate. While it is possible that widely separated regions could have the same climate, the most plausible explanation for this (and other) evidence is that the regions were once in close proximity. This line of reasoning should have been provided to help students make sense of the phenomena that support Wegener's idea of continental drift. Similarly, the identical rock formations and coal in Antarctica have comparable shortcomings.

A few phenomena are presented for the key ideas that the Earth's crust consists of separate plates that are moving (Idea g) and that landforms and geologic events are caused by the motion of these plates (Idea h). For example, a photograph shows a section of the San Andreas fault and the caption explains that the fault "results from two plates sliding past one another" (Level Green, p. 464s), the Great Rift Valley of Africa is mentioned as "a spreading center" (Level Green, p. 464t), and the Atlantic Ocean is mentioned as getting wider each year (Level Green, p. 464s).

Throughout the material, students are called upon to make models of processes (such as a convection current [Level Green, p. 462s]; a landslide [Level Green, p. 489s]; a stream table [Level Green, pp. 500-501s; 503s]; an ice flow [Level Green, p. 514s]; folds and faults [Level Red, p. 361s]; and earthquakes [Level Red, p. 363s]). None of the models involve students in thinking about how a model is like or unlike the real event or process, although, occasionally, students are asked to compare their model to a photograph (e.g., folds and faults [Level Red, p. 361s]). Some of the key Earth science ideas are not represented. Among them are that slow but continuous processes can produce significant changes in the surface of the Earth over time (Idea e) and that the surface of the Earth is changing continually (Idea a).

Very few practice questions are provided for the idea that matching coastlines and other evidence suggest that the continents were joined long ago as a single vast continent (Idea f). For example, students are asked to rewrite a letter that they wrote earlier in the chapter to the Royal Geological Society about the evidence for continental drift, so that the revised letter contains additional information to make it more persuasive (Level Green, p. 468s).

There are a few practice questions for the idea that the Earth's surface is changing continually (Idea a). One of them asks students to write how their neighborhoods have changed in the last 300 years and how they think they will change in the next 300 years (Level Green, p. 476t). A few questions are provided for the idea that several processes contribute to changing the surface of the Earth (Idea b), namely, that students make a display showing how weathering has affected their schoolyard (Level Green, p. 485t), write a paragraph about down-slope movements (Level Green, p. 490s), and write a story or draw a picture about the formation of a volcano (Level Red, p. 380s).

No practice problems are provided for the ideas that the processes that shape the Earth today are similar to the processes that shaped the Earth in the past (Idea c), that some Earth-shaping processes are slow while others are fast (Idea d), and that slow but continuous processes can create significant changes to the surface of the Earth over time (Idea e).

For example, after reading about plate tectonics and plate motion and being presented with a diagram of the Earth's plates, students are asked questions that include the following: "To which continents was North America once joined?" and "How can you explain the coal deposits found in Antarctica?" (Level Green, p. 465s). Although these questions are both related to the idea that the Earth's continents were once joined (part of Idea f), they do not build from understanding the evidence to an understanding of the key idea. In another example, having previously read about how Niagara Falls has changed in the past, students are shown a diagram of the receding falls. Questions are provided to guide their understanding of the reading and the diagram. Furthermore, the questions are intended to lead them to the idea that Niagara Falls is changing still and will continue to move in the future (Level Green, p. 476s). But no questions help students make connections between their own ideas and what they have read. Many of the model-making activities are followed by series of questions that may guide students. For example, after students use clay to model how earthquakes occur, they are asked: "What does each block of clay represent?" "What does each layer represent?" "What is simulated by the boundary between the two clay blocks?" "What would happen to a fence that crossed the fault?" and "Compare your model with the fault in the photograph on page 361" (Level Red, p. 363s). These questions may help students understand the model better and see how it relates to the real phenomenon. However, other activities either do not provide as much guidance or ask students only to summarize what they have observed (e.g., Level Green, p. 503s).

This material includes many assessment tasks that align with key Earth science ideas. However, a few of the ideas are not adequately assessed, and one key idea-the idea that Earth-shaping processes range from the very abrupt to the very slow (Idea d)-is not assessed at all.

The number of items that assess each key Earth science idea varies. For the idea that today's Earth-shaping processes are similar to those in the past (Idea c), a single item is included that has students explain the phrase, "[T]he present is the key to the past" (Level Green, p. 522st, question 2). The idea that the Earth's surface is changing continually (Idea a) is assessed with two questions: Students consider the changes that may have occurred while Rip van Winkle slept for 20 years (Level Green, p. 492st, question 4) and list evidence to convince Jerome (who believes that the Earth was always the same as it appears today) that the Earth has changed over time (Level Red, Chapter 17 Assessment, p. 274, item 5). Similarly, two items focus on the idea that several processes contribute to the changing of the Earth's surface (Idea b). Students consider what changes may have occurred while Rip van Winkle slept for 20 years (Level Green, p. 492st, question 4) and describe possible explanations for a list of observations (p. 520st, question 2). Other assessment items that appear to focus on this key idea require more specific knowledge of the processes that shape the Earth. For example, an item that has students explain "how deep trenches in the ocean floor and nearby mountain peaks are related to each other" (Chapter 24 Assessment, p. 349, item 4) requires a more sophisticated knowledge of the processes involved with the motion of plates.

A sufficient number of items are aligned with the evidence for continental drift (Idea f). All of them occur in Level Green. Students consider whether different observations support the theory of continental drift (Chapter 24 Assessment, p. 349, item 2), write a sentence using the words "continental drift" and "fossils" (Unit 8, End-of-Unit Assessment, p. 361, item 1c), write a letter to convince the Royal Geological Society to consider the idea of continental drift (pp. 459st and 468st, question 2), suggest an alternative explanation for the reptile fossils in South America and Africa (p. 468st, question 3), and list "some evidence that supports the theory of continental drift" (p. 522st, question 4). An even greater number of items are provided for the idea that the solid crust of the Earth consists of separate plates that move very slowly (Idea g) (e.g., Level Green, Chapter 24 Assessment, pp. 349-351, questions 1b, 3, 4, 5, 6, and Level Red, Chapter 16 Assessment, pp. 268-270, questions 1, 2, 3, 5, 6).

For example, after students have been introduced to the idea of plate tectonics, the Assessment component has them create models of the Earth's interior and the Reteaching component has them use the map of the world and what they know about plate tectonics to identify ten cities that are likely to be vulnerable to earthquakes (Level Green, p. 467t). In only one instance do the Assessment and Reteaching components focus on the same key idea: the Assessment component has students decide whether statements such as, "Volcanoes can occur only in certain places," are accurate, and the Reteaching component has them explain "why earthquakes and volcanoes tend to occur in predictable locations" (Level Red, p. 378t). Furthermore, while some relevant questions are included, SciencePlus does not include suggestions for teachers about how to probe beyond students' initial responses to better understand where they are in their learning, nor does it include specific suggestions for them about how to use students' responses to make decisions about instruction.

The material provides some sufficiently detailed answers to questions in the student text for teachers to understand and interpret various student responses. While the material usually provides correct, well-developed answers to questions, little additional information is provided on how to field potential student questions or difficulties (e.g., Level Red, p. 359t, Answers to An Earth-Moving Thought Experiment; Level Green, p. 485t, Answers to Questions [Simulation 3]). In addition, some answers are brief and require further explanation (for example, "Accept all reasonable responses" [Level Red, p. 364t, Homework]).

The material provides minimal support in recommending resources for improving the teacher's understanding of key ideas. While the material presents lists of references (including books, films, videotapes, software, and other media with addresses for ordering) that could help teachers improve their understanding of key ideas (e.g., "Glenn, W. H. 'Drifting: Continents on the Move.' The Science Teacher, February 1983" [Level Green, p. 449A]), the lists lack annotations about what kinds of information the references provide or how they may be helpful.

The material provides many suggestions for how to respect and value students' ideas. Introductory teacher's notes about concept mapping respect and value students' ideas by stating that "there is no single 'correct' concept map" (p. T39), but also give teachers some guidance about general characteristics of good maps. In addition, students and their ideas are highlighted throughout the text. For example, photographs and dialogue balloons present students discussing scientific ideas to be studied (e.g., Level Green, p. 471s). Students are specifically referenced in some student tasks (e.g., Level Red, p. 357s, In-Text Question C). In addition, the material explicitly elicits and values students' ideas in some text passages (e.g., Level Red, p. 389s) and in many tasks. For example, teacher's notes associated with text about rock terminology respect and value students' ideas by suggesting that students develop their own definitions for terms as they work through the unit and then brainstorm as a group to develop final definitions at the end of the unit (Level Red, p. 390t, Fiery Language).

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 how they know something or to provide evidence in their responses (e.g., Level Green, p. 450t, Unit Focus; Level Green, p. 458st, In-Text Questions and Something to Think About).

The material provides many suggestions for how to avoid dogmatism. Introductory teacher's notes provide suggestions for avoiding dogmatism though the use of guiding principles such as,  "Anyone can learn science" and "Science is a natural endeavor" (p. T17). Introductory teacher's notes also explain the STS (science, technology, and society) approach of the material that "teaches science from the context of the human experience and in so doing leads students to think of science as a social endeavor" and "emphasizes personal involvement in science" (p. T35). In accordance with the introductory guiding principles, the student text portrays the nature of science as a human activity in which students participate (e.g., Level Green, p. 479st, Exploration 2), and it describes changes over time in scientific thinking (e.g., Level Red, pp. 356-358s). In addition, the material includes some text passages and special features illustrating the work of particular practicing scientists (e.g., Level Green, pp. 515-516s) and highlighting the contributions of specific cultural groups (e.g., Level Green, p. 475t, Multicultural Extension).

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 interactions may be gained from student dialogues about the scientific ideas studied (e.g., Level Red, p. 394s) and procedural directions and descriptions of student roles in cooperative group activities (e.g., Level Green, p. 484t, Cooperative Learning: Exploration 5; Level Red, p. 388t, Cooperative Learning: Exploration 3; pp. T41-T46, Cooperative Learning).

The material provides some illustrations of the contributions of women and minorities to science and as role models. Most of the contributions of female and minority scientists, however, appear in a few special features at the end of each unit. For example, one Science in Action feature focuses on the work of Cristy Mitchell, a female meteorologist with the National Weather Service, who uses many forms of data-including standard weather measurements such as temperature, air pressure, and wind speed along with maps, radar, and satellite imagery-to study and predict weather patterns (Level Blue, p. 287st). In addition, Multicultural Extension teacher's notes within chapters highlight specific cultural contributions related to chapter topics (e.g., Level Red, p. 380t). 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 and teacher's notes.

The material suggests multiple formats for students to express their ideas during instruction, including individual ScienceLog writing (e.g., Level Red, p. 354s, ScienceLog), cooperative group activities (e.g., Level Green, p. 452t, Prior Knowledge and Misconceptions), laboratory investigations (e.g., Level Red, p. 361st, Exploration 1), whole class discussions (e.g., Level Green, p. 453t, Getting Started), essay questions (e.g., Level Green, p. 489st, Exploration 6 and Answers to Exploration 6), concept mapping (e.g., Level Green, p. 501t, Extension), creative writing (e.g., Level Green, p. 451t, Using the Photograph), play acting (e.g., Level Red, p. 380st, item 5), visual projects (e.g., Level Red, p. 375t, Homework), and oral presentations (Level Green, p. 464t, Continental Facts). In addition, multiple formats are suggested for assessment, including individual ScienceLog revising (e.g., Level Green, p. 469st, ScienceLog), oral discussion (e.g., Level Green, p. 501t, Assessment), essay (e.g., Level Green, p. 505t, Assessment), performance (e.g., Level Red, p. 369t, Assessment), portfolio (e.g., Level Red, p. 365t, Portfolio), and visual projects (e.g., Level Green, p. 455t, Assessment). In a few instances, the material also provides a variety of alternative formats for the same task (e.g., Level Red, p. 370t, Independent Practice).

The material does not routinely include specific suggestions about how teachers can modify activities for students with special needs. However, the Annotated Teacher's Edition and supplemental resources (including review, reinforcement, and enrichment work sheets and activities with transparencies) provide additional activities and resources for students and sometimes specify ability levels. The Annotated Teacher's Edition includes a Meeting Individual Needs feature that provides activities for students related to chapter topics and specifically designated for gifted learners, second-language learners, and learners having difficulties (e.g., Level Green, p. 458t; Level Red, p. 358t). For Spanish speakers, there are English/Spanish audiocassettes, which preview each unit in both languages. Also, in the Teacher's Resource Binder and Teaching Resources there are Spanish unit summaries, work sheets, glossaries, and English and Spanish Home Connection letters, which introduce parents to each unit and provide related home activities for students to do with parents. 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 when appropriate.

The material provides many strategies to validate students' relevant personal and social experiences with scientific ideas. Some text sections relate specific personal experiences that students may have had to the presented scientific concepts (e.g., Level Red, pp. 382-383s). In addition, some tasks ask students about particular personal experiences they may have had or suggest specific experiences they could have. For example, following a classroom activity in which students identify variables affecting the flow of streams using a stream table, they are asked to locate any of the same factors affecting stream flow in their own neighborhood. After describing these factors locally, they are then asked to identify any evidence of erosion from their neighborhood stream (Level Green, p. 501st, Outside the Classroom-A Project). For a few tasks, however, the material does not adequately link the specified personal experiences to the scientific ideas being studied (e.g., Level Red, p. 391t, Closure).