|Earth Science||Life Science||Physical Science|
1. About this Evaluation Report 2. Content Analysis 3. Instructional Analysis
|[Explanation] This section examines whether the curriculum material's content aligns with the specific key ideas that have been selected for use in the analysis.|
|[Explanation] This section examines whether the curriculum material develops an evidence-based argument in support of the key ideas, including whether the case presented is valid, comprehensible, and convincing.|
|[Explanation] This section examines whether the curriculum material makes connections (1) among the key ideas, (2) between the key ideas and their prerequisites, and (3) between the key ideas and other, related ideas.|
|[Explanation] This section notes whether the curriculum material presents any information that is more advanced than the set of key ideas, looking particularly at whether the “beyond literacy” information interrupts the presentation of the grade-appropriate information.|
|[Explanation] This section notes whether the curriculum material presents any information that contains errors, misleading statements, or statements that may reinforce commonly held student misconceptions.|
b: Several processes contribute to changing the
c: The processes that shape the Earth today are
similar to the processes that shaped the Earth
in the past.
d: Some of the processes are abrupt, such as earthquakes
and volcanic eruptions, while some are slow, such
as the movement of continents and erosion.
e: Slow but continuous processes can, over very
long times, cause significant changes on the
f: Matching coastlines and similarities in rocks
and fossils suggest that today’s continents
are separated parts of what was a single vast
continent long ago.
Paleontologists found fossils of an ancient
fernlike plant called Glossopteris in South America, Africa,
India, Australia, and Antarctica. The seeds of Glossopteris
are too heavy to have blown across oceans by wind. Scientists
infer from this evidence that all these continents were
connected at one time. [p. 93s]
g: The solid crust of the Earth consists of separate
plates that move very slowly, pressing against
and sliding past one another in some places, pulling
apart in other places.
h: Landforms and major geologic events, such as
earthquakes, volcanic eruptions, and mountain
building, result from these plate motions.
Science Insights: Exploring Earth and Space asserts most of the key Earth science ideas and provides some activities to illustrate them but does not provide an evidence-based case for them. However, the text makes some attempt to build a case for the key idea that matching coastlines and similarities in rocks and fossils suggest that today’s continents are separated parts of what was a single vast continent long ago (Idea f).
This key idea states the evidence (matching coastlines, similarities in rocks, similarities in fossils) and the conclusion drawn from it (today’s continents are separated parts of what was a single vast continent long ago). Sometimes the text provides an argument that explains why the evidence supports the conclusion. For example, after stating that Glossopteris fossils were found on several now widely separated continents, the text points out that the seeds are too large to have been carried by the wind. This refutes one alternative explanation before stating the conclusion that “Scientists infer from this evidence that all these continents were connected at one time” (p. 93s). However, the text does not explain why finding the same fossil in now quite different climates requires an explanation. Given that fossils typically are found where organisms once lived, it is likely that these locations once 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. In another instance, the text presents an argument and the conclusion but fails to adequately describe the evidence: “Rocks found in parts of South America, Africa, India and Australia all show evidence of glaciers at the end of the Paleozoic Era. For these places to have glaciers, they had to be closer to the South Pole” (p. 94s).
The text does not describe how the rocks showed evidence of glaciers. Furthermore, essential background information about sedimentation, folding mountains and glacial features are not presented until later in the textbook (sedimentation in chapter 10, mountain building processes in chapter 6, and glaciers in chapter 12). Therefore, many pieces of evidence presented—such as, “On both continents, for example, there are mountain ranges formed by folding of the crust” and “the rocks also show the direction in which the glaciers traveled” (p. 94s)—are not likely to make sense to students. Although some of the evidence for an ancient supercontinent is presented, students are not likely to understand the significance of the evidence.
Science Insights: Exploring Earth and Space presents most of the key ideas in six chapters (4, 5, 6, 7, 11, and 12). Very little attention is given to the time frames of Earth-changing processes (Idea d), and that the surface of the Earth is constantly changing (Idea a). The idea that small, seemingly unnoticeable changes can accumulate over long time frames to create significant features on the Earth (Idea e) is not mentioned at all. Thus, this textbook presents an incomplete story of how the surface of the Earth changes.
Although experiences and examples of several of the key ideas are provided, there is almost no attempt to tie together all the experiences provided for individual key ideas. For example, discussion of the many processes that shape the Earth (streams, glaciers, wind, mountain building, volcanoes, and earthquakes) is distributed among several chapters, but there are no statements, questions, or activities that convey to students the fact that several of these processes often act at the same time on the same land feature.
The evaluation teams’ collective findings, presented below, should be taken as having general applicability to all of the evaluated materials, not complete and specific applicability in toto to any one of them.
Identified errors occur most frequently in drawings and other diagrams. They take the form of representations that are likely to either give rise to or reinforce misconceptions commonly held by students. Following are Earth science examples of the kinds of misleading illustrative materials of most concern to the evaluation teams:
- Maps that do not show the accurate locations of earthquakes and volcanoes will prevent students from understanding the relationship between these events and plate boundaries. Likewise, diagrams and maps that do not include legends, and photographs that do not explain the size and scale of the object seen, are difficult for students to understand.
- Diagrams that (a) depict plates moving away from one another, thus exposing the mantle, (b) show the mantle very close to the surface of the Earth, or (c) show plates as being a layer under the crust inaccurately represent the structure of the Earth and the motion of plates.
- Diagrams that show the melting of subducted plates are incorrect. Subducting plates are known to cause melting in the mantle, and thus nearby volcanic activity, but the plates do not melt.