The TIMSS conducted in 1995 provides information about how laboratory experiences are treated in textbooks and state curriculum frameworks. As part of TIMSS, experts gathered information about curriculum standards and textbooks in almost 50 countries for 13-year-old students (8th graders in the United States) and for students in their final year of secondary education. The final-year students included “generalists,” those who were in vocational programs, and “specialists,” those taking advanced courses in physics.

The study sampled curriculum guides and textbooks in the participating countries. Curriculum guides were defined as official documents that most clearly reflected the intentions, visions, and aims of curriculum makers. In the United States, where national guides are not available, state guides were analyzed.⁵ Importantly, any lab manuals provided with a textbook were included in the analysis. Guides and textbooks were selected to represent those in use with at least half of the students in the targeted grade.

The TIMSS researchers developed a common framework to analyze the science curriculum materials across all countries. The framework included performance expectations, some of which are clearly relevant to laboratory experiences:

• theorizing, analyzing, and solving problems;

• using tools, routine procedures, and science processes; and

• investigating the natural world.

The researchers found that, although U.S. state curriculum guides for 8th grade science education referred to each of the three expectations, less than 10 percent of textbook content was devoted to helping students develop these laboratory-related abilities. They found textbooks in most other countries studied devoted a similarly low level of attention to these performance expectations, except for Germany, Hong Kong, and New Zealand, where coverage was slightly greater (21-40 percent of textbook content).

For 12th grade students taking advanced physics in the United States, no information was available from state curriculum guides, and only 10 percent of the content of textbooks addressed these three performance expectations related to laboratory experiences. This degree of coverage was similar to that in other countries. These results suggest that textbooks and the materials accompanying them give little attention to the learning goals of laboratory experiences, even though they may be identified as a priority in state science standards and curriculum guides.

The lack of attention to laboratory experiences in curriculum guides and textbooks may reflect state policies emphasizing coverage of a broad range