topics outlined for a grade level or science course. When they view laboratory experiences as isolated events that do not contribute to mastery of topics and science class time is short, laboratory experiences may be limited. For example, research on integrated instructional units has shown that engagement with laboratory experiences and other forms of instruction over periods of 6 to 16 weeks can increase students’mastery of a complex science topic, including the relationships among scientific ideas related to that topic. But teachers who try to “cover” an extensive list of science topics included in state science standards within a school year may have only a few days for each topic, precluding use of such potentially effective instructional units.
The interpretation and implementation of state science standards may also limit attainment of the educational goals of laboratory experiences in other ways. When state standards are seen primarily as lists of science topics to be mastered, they support attainment of only one of the many goals of laboratory experiences—mastery of subject matter. Some state standards call for students to engage in laboratory experiences and to attain other goals of laboratory experiences, such as developing scientific reasoning and understanding the nature of science. However, assessments in these states rarely include items designed to measure student attainment of these goals.
Conclusion 6: State science standards that are interpreted as encouraging the teaching of extensive lists of science topics in a given grade may discourage teachers from spending the time needed for effective laboratory learning.
Conclusion 7: Current large-scale assessments are not designed to accurately measure student attainment of the goals of laboratory experiences. Developing and implementing improved assessments to encourage effective laboratory teaching would require large investments of funds.
Laboratory experiences have the potential to help students attain several important learning goals, including mastery of science subject matter, increased interest in science, and development of scientific reasoning skills. That potential is not being realized today.
The committee does not recommend any specific policies or programs to enhance the effectiveness of laboratory experiences, because we do not consider the research evidence sufficient to support detailed policy prescriptions. A serious research agenda is required to build knowledge of how