for the Middle Grades Science Textbooks Evaluation
Earth Science
While research on students’ ideas about Earth science topics
is limited, the following student difficulties related to the key
ideas that serve as the basis for the middle grades Earth science
analysis have been noted:
- Students may think that the world was always as it is now or that any changes that have occurred must have been sudden and comprehensive (American Association for the Advancement of Science [AAAS], 1993, p. 336).
- The idea that water expands when freezing is difficult for students to accept. Because of this, students may have difficulty in accounting for the breaking of rocks when water freezes within them (Driver, Squires, Rushworth, & Wood-Robinson, 1994, p. 114). Note that while this has not been examined in the context of Earth science, it might be anticipated that students will have this difficulty.
- The formation of soil is strongly associated with deposition by rivers, although there is an alternative view that soil has "always been there ever since the earth was formed." Students’ ideas about the age of the soil vary—some think it is quite young while others think it is as old as the Earth. A notion widely held is that soil is the precursor of rock and that it changes to rock in the sequence: soil-clay-rock (Driver et al., 1994, p. 114).
Life Science
Research indicates that students typically have several difficulties
with the key ideas that serve as the basis of the middle grades life
science analysis:
- Students think that food is whatever nutrients organisms must take in if they are to grow and survive rather than those substances from which organisms derive the energy they need to grow and the material of which they are made (AAAS, 1993, pp. 120, 342; Driver et al., 1994, p. 27).
- Students think that food is a requirement for growth rather than a source of matter for growth (AAAS, 1993, p. 343; Driver et al., 1994, p. 60).
- Students think that plants get their food from the environment (mainly from the soil) rather than manufacture it themselves (AAAS, 1993, p. 342; Driver et al., 1994, p. 30).
- Students think that plants have multiple sources of food rather than that plants make food from water and carbon dioxide in the air, and that this is their only source of food (AAAS, 1993, p. 342; Driver et al., 1994, pp. 31, 60).
- Students may think that organisms and materials in the environment are very different types of matter and are not transformable into each other (AAAS, 1993, p. 342).
- Students may not believe that a plant’s mass may increase mainly due to the incorporation of matter from carbon dioxide (a gas) (Driver et al., 1994, pp. 32, 39).
- Students may think that plants do not respire, or that they respire only in the dark (Driver et al., 1994, p. 34).
- Students tend to regard food that is eaten and used as a source of energy as belonging to a food chain, while the food that is incorporated into the body material of eaters is often seen as something different and is not recognized as the material that is the food at the next level (Driver et al., 1994, p. 35).
- Students may think that dead organisms "rot away"; they do not realize that the matter from the dead organisms is converted into yet other materials (AAAS, 1993, p. 343).
- Middle school students seem to know that some kind of cyclical process takes place in ecosystems. Some students see only chains of events and pay little attention to the matter involved in processes such as plant growth or animals eating plants. They think of the processes in terms of creating and destroying matter rather than in terms of transforming matter from one substance to another. Other students recognize one form of recycling through soil minerals but fail to incorporate water, oxygen and carbon dioxide into matter cycles. Students may see no connection between the oxygen/carbon dioxide cycle and other processes involving the production, consumption, and use of food (AAAS, 1993, p. 343; Driver et al., 1994, p. 65).
- Students may think that matter and energy are converted back and forth in everyday (non-nuclear) phenomena (Schneps & Sadler, 1988).
Physical Science
Research indicates that students typically have several difficulties
with the key ideas that serve as the basis of the middle grades physical
science analysis:
- Students may think that everything that exists is matter (including heat, light, and electricity). Alternatively, they may believe that liquids and gases are not matter (AAAS, 1993, p. 336).
- Students have difficulty understanding the particulate nature of matter. For example, they may think that particles (atoms or molecules) are in substances, rather than that substances are made of molecules and/or that there is something (for example, air) between the particles (AAAS, 1993, p. 336; Driver et al., 1994, pp. 92–94).
- Students have difficulty appreciating the intrinsic motion of particles in solids, liquids, and gases (AAAS, 1993, pp. 75, 337; Driver et al., 1994, pp. 92, 93).
- Students attribute macroscopic properties to particles (such as hardness, hotness/coldness, expansion, physical state, and so on) (AAAS, 1993, p. 337; Driver et al., 1994, p. 92).
- Students have problems in conceptualizing forces between particles (AAAS, 1993, p. 337; Driver et al., 1994, p. 9).
References
American Association for the Advancement of Science. (1993). Benchmarks
for science literacy. New York: Oxford University Press.
Driver, R., Squires, A., Rushworth, P., & Wood-Robinson, V. (1994).
Making sense of secondary science: Research into children's ideas.
New York: Routledge.
Schneps, M. H., & Sadler, P. M. (1988). A private universe. New York: Annenberg/CPB.
