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AAAS :: Project 2061 :: Textbook Evaluations

Middle Grades Science Textbooks: A Benchmarks-Based Evaluation

Science 2000. Decision Development Corporation, 1995
Earth Science Life Science Physical Science

1.
 About this Evaluation Report
2.
 Content Analysis
3.
 Instructional Analysis
  Categories
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.
  References

I. Providing a Sense of Purpose

Conveying unit purpose (Rating = Very good)

Science 2000 excels in organizing each unit around an interesting story line that frames the unit and the lesson clusters within it and gives a purpose to students. Each of both the units and clusters is titled with an investigative question or questions that indicate what will be studied in the unit or cluster. The lesson plans provide teachers with the unit and cluster questions and a motivating story line to frame each unit and its clusters. The story lines and questions vary in quality. Usually, they are comprehensible and likely to be interesting and motivating to students. For example, in a sixth-grade unit, students are asked to design a nutritious snack food that meets the school board’s health requirements. The story line begins:
We have been challenged by a school board member to design a nutritious school snack. Sound easy? Where will we begin? In order to meet this challenge and convince the school board to approve our plans, we will have to become knowledgeable about many aspects of food and its preparation. We may know a great deal about foods from their smell, taste, and appearance. But what is it that makes some things tasty, edible, and nutritious, while other things are inedible, unhealthy, or even poisonous?
To answer these questions, we need to put on our chemist’s hat! What does chemistry have to do with it? SUGAR! STARCH! CHEMICALS! FATS!—These are featured in some of our favorite foods. Have you ever heard warnings to avoid them? Chemists recognize these substances as some of the essential ingredients in the foods we eat. Once we understand a little about the basic chemistry of food, we can learn what makes foods healthy and nutritious.
But why do our bodies need food? To answer this question, we will explore how the substances in food react in our bodies, and how our digestive systems break down food into substances our bodies can use. We will learn why so many different substances found in food, including vitamins and minerals, are important for good health. We will also investigate why some foods are called “junk food” and others “health food.” All of this will help us understand what kinds of foods the board might consider healthy.
Finally, we will learn where the substances in food come from. We will discover that some of the foods we eat may have once been part of a great tree, an animal, or a mountain. We will also learn why we can say our bodies are “solar-powered,” and why we should be very thankful for earthworms, mushrooms, and even bacteria! [6.4.25, LP, pp. 1–2]

However, on occasion, the questions are rather abstract and dry, as for example:

What is an environment, and what types of environments occur on the Earth? How have environments changed over time, and how have organisms adapted to these environmental changes? How do organisms, climate, and the natural surroundings affect the environment? How can you tell the story of the environment where you live? [grade 6, Teacher’s Guide, Chapter 10: Scope and Sequence, p. 10.3, unit 6.1]

Sometimes, teachers are instructed to present and discuss the unit and cluster story lines with students. That approach, in principle, would give students a chance to think about the purpose. For example, in the lesson plan quoted above, teachers are instructed to “[w]rite a list of potential foods on the board and ask students whether or not they think the items are foods. Summarize or read the unit story line and then lead a discussion about it” (6.4.25, LP1, p. 8). The lesson plan suggests the following discussion questions, which will give students the opportunity to think about what they will be doing in the unit and why:

Ask students to name some favorite foods they wish the school would serve. Do students consider these to be healthy? Why or why not? What are some foods they think the school board would consider healthy? [6.4.25.1, LP1, p. 9]

Students then generate a list of questions that they think they will need to answer in order to design healthy snacks and plan acceptable menus for their school cafeteria [6.4.25.1, LP1, pp. 9–10].

The clusters are consistent with the unit questions, and the lessons are mostly consistent with the cluster questions. However, while the link between the lessons and the unit purpose may be clear to an adult who has spent considerable time trying to understand it, the link may not be evident to students as they go through the material. For example, in a seventh-grade unit on the kuru mystery, students consider why members of the Fore tribe are dying. The unit involves students in examining the effects of various physical factors in the environment on a model system—seed germination (7.1.4). Unfortunately, it is unlikely that students will appreciate why seed germination is a good model system for studying the effects of physical factors on human health. Therefore, a lesson on parts of the human respiratory system and their functions may not be seen as relevant to the unit or cluster question.

Conveying lesson/activity purpose (Rating = Fair)

Science 2000 is inconsistent in conveying the purpose of lessons and activities. Most of the time, purposes are provided for the lessons but not for the activities within the lessons. An investigative question serves as the title for each lesson. Sometimes, teachers are instructed to convey this question to students and discuss it with them, although this is more typical of the sixth-grade lessons (e.g., 6.4.25.1 and 6.4.25.3) than the seventh-grade ones (e.g., 7.1.4.1 and 7.1.4.2). Student investigations begin with a statement of purpose (e.g., all four investigations in 6.1.2). The questions vary in comprehensibility. The fifth-grade questions tend to be about abstractions—for example: “How do ocean waters support life? What is an ocean food web?”—that students are not likely to find understandable (5.1.1.4, LP4, p. 29). However, the sixth- and seventh-grade questions are likely to be understandable, particularly when accompanied by the suggested discussions. In some cases, students are able to discuss the investigative questions (e.g., 6.1.2.1, 3, 4 and 7.1.4.1). In other cases, they are asked questions that set the stage for activities, but the questions are not explicitly about the purpose (e.g., 6.1.2.2). Most of the sixth-grade lessons relate well to the unit or cluster purpose, but the seventh-grade lessons vary in that regard. Periodically, students are told what they have learned so far and what they will learn or do next (in grade six but not in grade seven). They are rarely given a purpose when asked to explore databases.

Justifying lesson/activity sequence (Rating = Satisfactory)

Although each unit contains an outline of the investigative questions for clusters and lessons, it does not offer a rationale for their sequence. Nonetheless, the cluster story lines weave the questions together in an interesting way, and the questions seem to flow well. For example, after students are challenged to design a nutritious snack food that meets the school board’s approval, there is the following sequence of lesson questions:
Lesson 1: “What is food? What substances are found in food?” Lesson 2: “Why do we need food? How do our bodies use food?” Lesson 3: “What are vitamins and minerals? Why do we call some foods junk food or health food?” Lesson 4: “Where do the substances in food come from? How is food produced?” [6.4.25, LP, p. 2]

The same is true in the seventh-grade kuru unit, in which, after being challenged to solve the mystery of why members of the Fore tribe are dying, students proceed to consider and then eliminate various suspects—the social behavior of the tribe, environmental factors, nutrition and diet, infection, and heredity (7.1). Sometimes, the rationale for putting particular activities in a particular sequence is not very evident. For example, in grade 6, unit 4, cluster 25, it is not clear why the activity in which students test foods for solubility is included (6.4.25.1, SI25–1–A).





II. Taking Account of Student Ideas

Attending to prerequisite knowledge and skills (Rating = Poor)

Prerequisite knowledge and skills are not dealt with adequately. The sixth-grade food unit (which defines food in terms of its molecular components) depends on students understanding the prerequisite ideas that matter is composed of atoms and that atoms combine to form discrete molecules. These prerequisite ideas are treated in an earlier sixth-grade unit (6.3.21.1) in the context of examining the properties of building materials, but the only mention that they are necessary knowledge for the food unit comes from a parenthetical statement to the teacher: “If students are unfamiliar with atoms and molecules, discuss or have students spend a few minutes exploring the Atoms, Molecules, and Chemical Notation Database before going on” (6.4.25.1, LP1, p. 11, procedure 5). It is not apparent from this statement what students should learn from these databases, and the food unit makes no explicit connection to the prerequisite ideas. The other important prerequisite idea—that energy can be changed from one form to another in physical systems—is not mentioned. Energy transformation in biologic systems is less obvious than in physical systems. Hence, student understanding of energy transformation in biologic systems could benefit from experiences that trace where energy changes forms in physical systems—for example, light energy is transformed into heat energy; heat energy is transformed into mechanical energy. Yet, teachers are not alerted to this prerequisite or to experiences that students may have had with it in earlier units. Furthermore, a brief look at prior units indicates that they do not give students experiences related to energy transformation.

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

The Science 2000 makes no reference to any of the misconceptions commonly held by students about the flow of matter and energy in ecosystems that have been documented in research studies. For example, research on student understanding of ecosystems reveals that students envisage matter as being created or destroyed, rather than as being transformed (Smith & Anderson, 1986). Students who do see matter as being transformed think of it as being transformed into energy, rather than broken down into simpler substances. Students also view plants as taking in food from the environment (e.g., from the soil), rather than as taking in raw materials that they convert to food (Bell & Brook, 1984; Roth & Anderson, 1987; Anderson, Sheldon, & Dubay, 1990). Teachers are not alerted to these misconceptions that many students have.

Furthermore, in some cases, these troublesome ideas are reinforced in the material. For example, in a sixth-grade lesson on cellular respiration, the lesson plan states: “We are now ready to explore the basic chemical reaction in which food molecules are turned into energy in our cells” (emphasis added) (6.4.25.2, LP2, p. 17, procedure 7). This could reinforce easily a common student misconception that matter can be turned into energy, not only in nuclear reactions but also in everyday reactions in living organisms. The use of terms in grade five, particularly “nutrients,” could contribute to the common student misconception that plants get their food from the soil. On the one hand, students are told that nutrients provide energy for organisms and, on the other hand, that soil provides nutrients for plants (5.1.6.3).

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

Science 2000 conveys the importance it places on finding out students’ ideas about key life science concepts by including relevant questions and indicating their purpose. In describing the instructional approach, the Teacher’s Guide indicates that the first step of every lesson, called Introduction and Preassessment, “also provides the teacher with an opportunity to assess what students already know about a subject” (in grades five, six, and eight, Teacher’s Guide, p. 8.1). In nearly every lesson, there are questions designed to probe students’ initial knowledge of key life science ideas, and there are questions for nearly all of the key ideas. For example, to identify students’ beliefs about the concept that decomposers transform dead organisms into simpler substances, which other organisms can reuse, there is this question: “How are nutrients replenished in soils in natural settings?” (5.1.6.3, LP3, p. 17, procedure 3). To find out what students think food is, they are asked to “write their own definition of food,” identify which items on a list are foods, what the identified items have in common, and what defines a food (6.4.25.1, LP1, p. 9, procedure 1). To ascertain whether students realize that plants get their energy by breaking down some of the sugars they have synthesized, this question is posed: “Where did the grass get its energy and nutrients?” (6.4.25.4, LP4, p. 29, procedure 2). Most of the questions are comprehensible and require students to give explanations of phenomena or examples. Sometimes, there are even follow-up questions, but they seem to be trying to build a story line of correct answers instead of eliciting students’ ideas. For instance, before a discussion of photosynthesis, the carbon cycle, and tracing energy in food chains, students are asked to
write or draw in their notebooks the ingredients of these foods and where they think the ingredients came from. (For example, cookies contain flour from wheat, sugar from sugar cane, eggs from a chicken, and margarine or oil from corn or soybeans.) [6.4.25.4, LP4, p. 29, procedure 1]

After sharing their answers, teachers are to ask what students notice about these food sources, whether they noticed that many of the ingredients are from living things—plants and animals—and whether students included this information in their definitions of food in lesson 1.

Addressing commonly held ideas (Rating = Poor)

Science 2000 makes no attempt to address the misconceptions that many students have about some of the key life science concepts. Furthermore, in some cases, Science 2000 encourages several common misconceptions—the idea that matter and energy are interconvertible in living systems and the idea that plants take in their food from the soil. For example, in a sixth-grade lesson on cellular respiration, the lesson plan states: “We are now ready to explore the basic chemical reaction in which food molecules are turned into energy in our cells” (emphasis added) (6.4.25.2, LP2, p. 17, procedure 7). This could reinforce easily a common student misconception that matter can be turned into energy, not only in nuclear reactions but also in everyday reactions in living organisms. The use of terms in the fifth grade, particularly “nutrients,” could contribute to the common student misconception that plants get their food from the soil. In one place, students are told both that nutrients provide energy for organisms elsewhere and that soil provides nutrients for plants (5.1.6.3).




III. Engaging Students with Relevant Phenomena

Providing variety of phenomena (Rating = Poor)

While there is a content match for most of the ideas examined, Science 2000 contains phenomena that support only a few of them. Most of the phenomena address the idea that food serves as fuel and building blocks for all organisms (Idea a). Students examine food labels to determine calories and main ingredients; they test different foods for sugar, starch, fat, and protein; and they observe that more heat is given off when they burn buttered popcorn than unbuttered popcorn (6.4.25.1, 2). In addition, students watch a video showing a toy engine and a light bulb powered by burnt peanuts (but because not enough attention is given to this video, it is questionable whether it is comprehensible to students [see 6.4.25 video clips entitled “Using the Energy in Food” and “Energy from Food (Chemical Energy”)]). Even though it does not provide phenomena to show that all organisms, not only humans, get their energy and building matter from their food, Science 2000 does provide the most extensive set of phenomena for this idea compared to other middle school curriculum materials reviewed.

On the other hand, there are not nearly enough phenomena to illustrate the other key life science ideas. For example, to demonstrate that organisms break down sugars to get the energy they need, releasing some of the energy as heat (Idea d3), there are no phenomena at all. For the idea that organisms break down sugars into simpler substances (Idea c3), there is one phenomenon: Students observe that a mirror turns cloudy when they breathe on it and that limewater solution turns milky when they blow in it (7.1.14.4, SI4–4b). However, this phenomenon is not explained well in terms of this key idea; students read that water and carbon dioxide are the products of respiration, but no link is made to the idea that sugars are being broken down and matter transformed.

Providing vivid experiences (Rating = Fair)

Most of the phenomena described under the previous criterion that support the ideas that organisms get their energy and building materials from food (Ideas c3, d3) are efficient and vivid, except that the activity in which students test foods using food indicators is not as time-efficient as reading food labels. However, the few phenomena in Science 2000 that support the other key life science ideas do not provide students with a vicarious sense of the phenomena. For example, for the idea that plants make sugars from carbon dioxide and water (Idea c1), students observe what happens to plants grown in a variety of conditions: in the absence of water, in the presence of sodium hydroxide, in the light, in the dark, in the refrigerator, and so forth (7.1.4). Each group of students performs only parts of this investigation and reports its findings to the whole class. In some cases, one group tests a certain variable (e.g., growth in the dark), while a different group performs the experimental control (e.g., growth in the light). The investigation continues over several lessons, but it is unclear whether and how students will put together the various of findings.


IV. Developing and Using Scientific Ideas

Introducing terms meaningfully (Rating = Fair)

Science 2000 introduces terms in different parts/sections of the program. Student investigation sheets (which are included in the software) include certain terms as “hot buttons” that link to definitions of the terms in the glossary. So, presumably, if students view these sheets on the computer, they will explore their links. Lesson plans (which are also included in the software) sometimes include instructions to teachers about students looking up specific terms in the glossary. Lesson plans include in the procedure section additional terms linked to the glossary. However, it is not clear whether the students are able to view the lesson plans or, if not, whether and how the teacher is to introduce these additional terms to the students. Given these ambiguities, it is not always feasible to evaluate whether certain terms will or will not be introduced in the context of relevant experiences.

Most of the terms (even those that go beyond the terms needed for science literacy) are linked well to relevant experiences. For example, the term “decomposers” is introduced when considering the breakdown of dead organisms in a compost pile (5.1.6.3), “photosynthesis” appears in the discussion of a specific food chain (5.1.1.4), and “respiration” in the context of germinating seeds (7.1.4). However, some terms are not related to relevant experiences. For example, in 5.1.4.3, teachers are instructed to introduce the terms “producers,” “consumers,” “herbivores,” “carnivores,” and “omnivores” without giving students pertinent experiences with them. In grade five, “photosynthesis” is defined merely as the process of food-making.

While Science 2000 does not include many unnecessary terms that are commonly seen in middle school curriculum materials—such as “palisade,” “spongy layer of leaves,” “xylem,” and “phloem”—it does use nearly 20 other terms that are not needed to communicate information about the key life science ideas or relevant phenomena. For example, Science 2000 includes the names of types of consumers, ocean zones, and biomes. Furthermore, the detail used in presenting respiration goes beyond what is appropriate for the middle grades.

Representing ideas effectively (Rating = Fair)

Compared to other middle school curriculum materials, Science 2000 contains numerous representations of the key life science ideas. Unfortunately, several of them are inaccurate or incomprehensible. Moreover, most of these representations are in the databases and the videos, and there is little guidance to teachers about how to use them to clarify the key ideas.

In grade six, after students study food labels, it is suggested that they use molecular model kits (which need to be purchased separately) or toothpicks and marshmallows to build proteins, fats, sugars, and water molecules (6.4.25.2). Students are shown chemical formulas and molecular models of sucrose, protein, and starch. They watch a video showing the breakdown of sucrose, starch, protein, and fat and then write word and chemical equations for these breakdown reactions. They count the atoms on each side of the equation and conclude that the total number of atoms remains the same. Finally, they are shown a video of digestion and then discuss the analogy of food combustion to burning. (The digestion video should have mentioned that this is a simplification of a multistep process and that, in actuality, sugar is not broken down into individual atoms that recombine to form carbon dioxide.) Additional diagrams that might misinform students are included without being critiqued (see Fig. 25–7: The Carbon Dioxide-Oxygen Cycle, Fig. 25–18: Cellular Respiration, Fig. 25–19: Elements That Make Up Our Bodies).

In the last lesson before assessment in grade 6, cluster 25, students are introduced to the idea of photosynthesis. They see a video that compares the photosynthesis reaction to a building being erected (shown by time-lapse photography) and that displays an animation of the photosynthesis reaction. Students then write the chemical equation for photosynthesis. However, they are helped to see only that it is the reverse of the respiration reaction and not that certain substances are transformed into new substances. It also is suggested that students make “sunprints” of leaves using photosensitive paper “[t]o illustrate that sunlight can supply energy to cause a chemical reaction,” but no further guidance is given to develop this analogy (6.4.25.4, LP4, p. 30, procedure 3).

Demonstrating use of knowledge (Rating = Poor)

Science 2000 does not model the use of the key life science ideas. The only instance found was one task that demonstrates tracing energy in a food chain (6.4.25.4, LP4, p. 29, procedure 2), but it is listed as optional. Furthermore, it does not provide adequate guidance for teachers in how to use the key life science ideas in the demonstration.

Providing practice (Rating = Poor)

Overall, the number and variety of opportunities for students to practice using the key life science ideas are not adequate. While there are a few specific and novel practice tasks, there are no practice tasks like the ones below for all of the key life science ideas. For some of the key ideas, no practice tasks are provided. The following questions are in the culminating activity of the snack food unit:
Look at the important nutrients or molecules that are contained in this food. What kinds of elements or atoms make up most of these molecules? [6.4.25.5, SI25–5, p. 28, question 2]
Label where energy enters and leaves the food chain. Use blue arrows to show the movement of energy. [6.4.25.5, SI25–5, p. 29, question 6]
What is the chemistry of cellular respiration? Draw a picture of yourself. On the picture, write down which molecules or substances you take in as reactants in respiration and draw arrows showing them entering your body. What are the products of respiration? Write these down and draw arrows showing them leaving your body. Be sure to indicate whether energy is used or released in respiration and what happens to it. [6.4.25.5, SI25–5, p. 29, question 8]

For the ideas that plants make sugars from carbon dioxide and water (Idea c1) and that plants break down the sugars into carbon dioxide and water (Idea c2), there are one or two practice tasks on the order of: What must it [a plant] take in to make food? What is the chemical formula of the simple carbohydrate made by plants? What do plants do with the food they make? (6.4.25.5, SI25–5, p. 28, question 3). For the idea that decomposers transform dead organisms into simpler substances, which other organisms can reuse (Idea c4), there are no practice tasks.

Even when tasks are provided, there are no instances in which tasks or questions increase in complexity, nor are there opportunities for students to receive feedback so that they can improve their performance.


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

Encouraging students to explain their ideas (Rating = Fair)

Science 2000 routinely provides opportunities for students to express their ideas about the key life science ideas, but not to clarify, justify, or represent them. For example, after studying photosynthesis, students are asked: “Are these the only elements we get from foods?” “What other elements do we get from the fruits and vegetables we eat?” and “Where do the plants get the nitrogen they need to make the proteins and minerals that are found in many vegetables and fruits? (As a hint, you might ask students to think about why people fertilize plants)” (6.4.25.4, LP4, p. 32, procedure 6). Questions occasionally require students to make predictions or give explanations. For example, students are asked in what ocean zones they think photosynthesis takes place, where plankton are likely to live, and why they think so (5.1.1.4, LP4, p. 31; 5.1.1.4, SI1–4, p. 21); students also are asked to predict what will happen if a glass jar is placed over a burning candle and, after they observe the candle go out, to explain why they think it did (6.4.25.2, LP2, p. 16, procedure 2). In most cases, each student is given the opportunity to state his or her ideas in writing or in small group discussions. However, the text provides no feedback to students, nor do the teacher notes suggest how teachers can diagnose student misconceptions or give them evaluative or corrective information.

Guiding student interpretation and reasoning (Rating = Poor)

Science 2000 includes specific questions or tasks related to investigations and databases. Most of these questions emphasize interpretation of information provided. For example, after examining the Nutrient Cycles and Food Chains Database (6.4.25.4), students are reminded of the equations for photosynthesis and cellular respiration and then are asked: “Where do you think that plants get the carbon dioxide they need? (Some of it comes from the waste products of respiration in animals)” (6.4.25.4, LP4, p. 31, procedure 4). Similarly, students are asked to unscramble steps in the carbon and nitrogen cycles and to “refer to the Nutrient Cycles and Food Chains Database, the Animation of Respiration Reaction, and Cellular Respiration if you need help” (6.4.25.4, SI25.4, p. 25). Questions do not frame important issues (largely because students have few experiences with relevant phenomena), or anticipate common misconceptions. And only rarely are questions sequenced to lead students to the key life science ideas. In the few instances where question sequences are used, such as in the example below, the questions do not move students toward the key life science ideas. For example, after viewing a video on photosynthesis, teachers are to ask:
Did you learn anything more about how plants produce food? How? What is photosynthesis? Why is photosynthesis important? What happens during photosynthesis? What do you think might happen to the living organisms at your lake if there were no photosynthesis taking place? What would happen to the producers? What would happen to the consumers? Guide the class to realize that the interdependence of the lake organisms means that if there is no photosynthesis occurring, all levels of the food chains suffer; each level is dependent on the previous one. [7.2.12.1, LP1, p. 2]

Unfortunately, there are many missed opportunities for guiding students to interpret their investigations and readings in terms of the key ideas. This may reflect the authors’ lack of attention to the research literature dealing with many students’ beliefs.

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

Encouraging students to think about what they have learned is not a consistent feature of Science 2000, although students do have a few opportunities to revise their ideas. Notably, they are asked to change their thinking about what constitutes “food,” an essential foundation of the set of key ideas (6.4.25.1, LP1, p. 10, procedure 3). There are two other instances in which students are asked to revise their ideas. They are asked to reconsider, based on an examination of food labels, whether various junk foods are nutritious (6.4.25.3, SI25–3–B), and also to return to their preconceptions about the human respiratory system and the process of breathing, so that they can revise their notebook entries as needed. However, the nutritional value of junk food is not aligned with the key life science ideas, and the question about respiration is not sufficiently specific for students to know what ideas are to be rectified.

VI. Assessing Progress

Aligning assessment to goals (Rating = Poor)

Science 2000 systematically includes assessments for the clusters. However, in most cases, the purpose of the assessment is not to evaluate the key life science ideas—even in the clusters where those ideas are addressed extensively. Most of the key life science ideas are not assessed adequately in Science 2000. The only cluster that contains relevant assessment items is cluster 25 in grade six, which has a strong assessment lesson with tasks that are pertinent for the key life science ideas. Students are asked where a plant gets its energy and the nutrients it needs to make food. They draw a food chain, starting with the foods they bring to school, and indicate where energy enters and leaves the food chain and where the building blocks they need come from. They name the process by which plants make carbohydrates and write out the word equation. They describe what happens to the food in their bodies and identify the reactants and products for respiration. Apart from these questions, there are some that do not require knowledge of the specific key ideas (for example, tracing food to plants), and others that go beyond the scope of the key ideas (for example, writing the chemical formula of the carbohydrate produced by plants [6.4.25.5, SI25–5, p. 28, question 3]). While the assessments described above are aligned to the key ideas, there is an insufficient number of such assessment items.

Testing for understanding (Rating = Poor)

Science 2000 provides few assessment items that assess understanding of the key life science ideas. Of the relevant assessment items described under the previous criterion, some focus on understanding, as for instance: “What does your body do with food? How does it use food?” (6.4.25.5, SI25–5, p. 29, question 7). Also, students add arrows, labels, and drawings to their food chain diagrams tracing the flow of matter (questions 3, 5, 11) and energy (questions 6, 11).

Most of these tasks include familiar contexts with some minimally novel aspects. For example, question 8 asks students to draw a picture of themselves and add labels and arrows for the reactants and products of cellular respiration. While students may have memorized the equation for cellular respiration, it is a novel representation (6.4.25.5, SI25–5, p. 29).

Using assessment to inform instruction (Rating = Poor)

The professional development component of Science 2000 states that the strategy of devising instruction based on students’ performance is a powerful one, and it encourages the teacher to observe students in order to get informal feedback:
[Formative] assessment offers guidance for improvement and is an ongoing process. It can be formal…or informal…. Because many students work independently or in groups during Science 2000 lessons, the teacher is able to circulate in the classroom, observe students, and get informal feedback…. During lessons, teachers are encouraged to informally assess students’ comprehension by observing their progress at the activities. [in grades five, six, and eight, Teacher’s Guide, Teacher Tips, p. 19.3]

Elsewhere in the Teacher’s Guide, however, there is no explicit mention of this instructional strategy and no specific reference to questions or tasks. Assessment is discussed in the Science 2000 Instructional Approach (pp. 8.1–8.2), which specifies that questions in step 1 are for preassessment and they should be used to “guide the teacher in building bridges to new content” (p. 8.1), while those in step 5 (Evaluation) are for the “final step in a constructivist learning sequence” (p. 8.2). Step 5 notes that Science 2000 “outlines a variety of strategies for assessing the conceptual understanding achieved by students” and that “[t]here are structured assessment questions or assignments after many lessons and after each cluster.” It further notes that “[m]any of these engage students in the applications of concepts and knowledge” (p. 8.2). However, the role of these assessments in instruction is not made clear. Likewise, Chapter 13: The Science 2000 Software contains a paragraph on assessments that states:

Science 2000 includes short written tests of students’ conceptual understanding of each cluster.… Some of the assessments ask for quite specific information to check problem-solving and mathematical skills, while others ask for more formative responses, such as ideas the students had while conducting an investigation. [p. 13.8]

However, no mention is made of the function of the assessments in instruction.

Although not explicit, Science 2000 does have some opportunities for students to express and apply relevant ideas (see the above criteria entitled “Providing practice” and “Encouraging students to explain their ideas”), which, in principle, can be used by a well-informed teacher to diagnose students’ remaining difficulties. However, these opportunities are insufficient to assess the status of students’ knowledge with respect to the key life science ideas. Furthermore, while there are some appropriate questions, there are no suggestions for teachers about how to probe beyond students’ initial responses in order to acquire a better understanding of the level of their learning, nor are there specific suggestions about how to use students’ responses to make decisions about instruction.

VII. Enhancing the Science Learning Environment

Providing teacher content support (Minimal to 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 notes in the lesson plans usually provide sophisticated versions of ideas for each lesson. However, the advanced explanations often do not explicitly alert teachers to how ideas have been simplified for students (e.g., 6.4.25.2, LP2, pp. 12–14, Background) and sometimes present additional terms (e.g., 6.4.25.4, LP4, pp. 26–27, Background). Overall, the teacher content support may be used as a selective but not comprehensive content resource by the teacher.

The material provides some sufficiently detailed answers to questions in the student text for teachers to understand and interpret various student responses (e.g., 6.4.25.5, SI25–5, Teacher Answer Key, p. 31, item 7). However, there are some limitations to the responses provided in teacher’s notes, which are sometimes brief and require further explanation (for example, “The vegetable peelings would decompose more thoroughly with the help of the organisms” [5.1.6.3, SI6–3–B, Teacher Answer Key, p. 18, item 5]), or are absent (for example, no teacher answer key for 7.1.4.Assessments component).

The material provides minimal support in recommending resources for improving the teacher’s understanding of key ideas. The material includes lists of mediagraphy (film, video, and software), teacher articles, teacher books, and organizations in the Resources component of each cluster. However, the lists lack annotations about what kinds of information the references provide or how they may be helpful.

Encouraging curiosity and questioning (Some support is provided.)

The material provides a few general suggestions for how to encourage students’ questions and guide their search for answers. Introductory teacher’s notes in the Professional Development Teacher’s Guide state that “teachers can encourage students to develop their own questions and to conduct their own observations and experiments” (6.PD, p. 6.2). In addition, the introductory teacher’s notes describing teacher lesson plans state that “lessons are designed so students have to ask questions and figure out how to find the answers” (6.PD, p. 7.1). Specifically, in one lesson plan, teachers are instructed to “ask students to generate a list of questions they think they will need to answer in order to design healthy snacks and plan acceptable menus for their school cafeteria” (6.4.25.1, LP1, p. 10, Procedure, item 1[c]).

The material provides some suggestions for how to respect and value students’ ideas. Teacher’s notes state that multiple student answers should be acceptable for selected questions (e.g., 6.4.25.5, SI25–5, Teacher Answer Key, p. 31, items 1, 6), and the student text explicitly elicits and values students’ own ideas in some hypothesis and design tasks (e.g., 6.4.25.4, LP4, p. 33, Extensions, item 4).

The material provides a few suggestions for how to raise questions such as, “How do we know? What is the evidence?” and “Are there alternative explanations or other ways of solving the problem that could be better?” but 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., 5.1.16.3, SI6–3–B, p. 16, item 3; 7.1.15.4, SI5–4a, p. 130, Procedure, item 10).

The material provides some suggestions for how to avoid dogmatism. Introductory teacher’s notes emphasize the role of the teacher as “a facilitator and a question-asker, encouraging students to articulate what they already know and to draw on their knowledge as they pursue an investigation” (6.PD, p. 6.2). The student text portrays the nature of science as a human enterprise in which students may participate (e.g., 6.4.25.1, SI25–1–B, pp. 6–7), highlights the work of some current scientists in the Scientists in Action component (e.g., 6.4.25.Scientists in Action component, Stark, David) and illustrates changes over time in scientific thinking (e.g., 7.1.5.1, LP1, pp. 1–2, Procedure, item 1).

The material provides a few examples of classroom interactions through brief vignettes in the Science 2000 Professional Development Teacher’s Guide that illustrate appropriate ways to respond to student questions or ideas (e.g., 6.PD, pp. 1.1–1.2). In addition, a limited sense of desirable student-student interactions may be gained from procedural directions for laboratories and cooperative group activities (e.g., 6.PD, pp. 19.6–19.10; 5.1.4.3, LP3, p. 21, Procedure, item 3; 7.2.12.1, LP1, pp. 2–3, Procedure, item 4).

Supporting all students (Considerable support is provided.)

The material generally avoids stereotypes or language that might be offensive to a particular group. Video clips include a diverse cultural mix of adults and children (e.g., 6.4.25.2, LP2, Procedure, item 5, Enzyme Action; 6.4.25.Careers component, X-ray technician, X-ray technicians; 7.2.12.1, LP1, Procedure, item 3, video that explains how plants produce food). In addition, the material’s use of narrative dialogues (e.g., 6.4.25, LP, pp. 1–2, Storyline) along with traditional expository text may support the language use of particular student groups.

The material provides some illustrations of the contributions of women and minorities to science and as role models. Most of the contributions of women and minorities appear in the Scientists in Action component that lists name of scientists who have worked in the subject area with links to biographies sometimes including video, still photographs, and links to other databases. For example, the biography of physician and nutritionist Grace Arabell Goldsmith describes her work with vitamin-deficient diseases (e.g., 7.1.5.Scientists in Action component, Goldsmith, Grace Arabell [1904–1975]). In addition, some Option (e.g., 7.1.5.1, LP1, p. 6, Procedure, item 6, Option) features highlight cultural contributions related to chapter topics. The cultural contributions within these components are interesting and informative but may not be seen by students as central to the material because they are often presented separate from the main lesson plans and student investigations.

The material suggests multiple formats for students to express their ideas during instruction, including individual investigations (e.g., 7.1.5.5, LP5, p. 20, Procedure, item 5), journal or log writing (e.g., 6.4.25.1, LP1, p. 9, Procedure, item 1 [a]), cooperative group activities (e.g., 6.4.25.4, LP4, p. 31, Procedure, item 5), laboratory investigations (e.g., 7.2.12.1, SI12–1a and 7.2.12.1, SI12–1b, pp. 325–328), whole class discussions (e.g., 6.4.25.2, LP2, p. 18, Procedure, item 9), essay questions (e.g., 5.1.16.3, SI6–3–B, p. 16, item 4), and visual projects (e.g., 6.4.25.4, SI25–4, pp. 25–26). In addition, multiple formats are suggested for assessment, including oral discussion (e.g., 5.1.6.3, LP3, pp. 17–18, Procedure, item 3), essay (e.g., 6.4.SI25–5, p. 29, item 7), and performance (e.g., 6.4.25.5, LP5, p. 34, Procedure, item 1, Optional Assessment). However, the material does not usually provide a variety of alternatives for the same task but often includes additional optional activities (e.g., 6.4.25.2, LP2, p. 18, Procedure, item 8, Option).

The material does not routinely include specific suggestions about how teachers can modify activities for students with special needs. However, the material suggests that Extension activities may be used in place of parts of the lesson if deemed by the teacher to be “more appropriate for the class’ ability, background or interests” (6.PD, p. 7.1) and are later designated as suitable for gifted and advanced students (6.PD, p. 7.3). In addition, the material suggests that teachers provide opportunities for students to explore the database individually (6.PD, p. 18.4). For Spanish speakers, background descriptions of lessons, story lines, key concepts, many database entries, many student investigations, and other materials are written in Spanish and English (6.PD, p. 7.3). For hearing impaired students, the audiotrack of the video clips has close-captioning. For visually impaired students, some text is written in large type. Teacher tips provide additional suggestions for supporting limited English proficiency and bilingual students (e.g., 6.PD, pp. 19.5–19.6, Computer Instruction with Language Minority Students).

The material provides many strategies to validate students’ relevant personal and social experiences with scientific ideas. Many tasks ask students about particular personal experiences they may have had or suggest specific experiences they could have. For example, students are asked to trace the matter in one of their own meals to its origins and then create a food chain of the process (6.4.25.4, LP4, p. 29, Procedure, item 2). 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., 6.4.25.4, LP4, p. 33, Extensions, item 3).

Advancing science, Serving society

Copyright 2002 by the American Association for the Advancement of Science. All rights reserved.