Laboratory Instruction in the Service of Science Teaching and Learning: Reinventing and Reinvigorating the Laboratory Experience.

The Benchmarks for Science Literacy (AAAS 1993) and the National Science Education Standards (NRC 1996) strongly suggest that students should be engaged in hands-on learning. However, from many corners, the original "mental training" rationale for school labs has been criticized, the "cookbook" nature of laboratory exercises condemned, and the prevalence of using laboratories simply to verify previous classroom content questioned. These attacks are justified. Too frequently the school laboratory is far removed from the recommendations of constructivist teaching and is at odds with the way scientists themselves investigate problems. [ILLUSTRATION OMITTED] Abd-El-Khalick et al. (2004) illustrate that inquiry is again becoming a dominant theme in science curricula policy discussions, both in the United States and throughout the world, with the laboratory suggested as the natural domain of inquiry instruction. The impact of inquiry teaching on learning is impressive. Smith (1996) and Mao and Chang (1998) in their meta-analyses of inquiry teaching conclude that inquiry methods of teaching science resulted in significantly improved mastery of science content, content retention, enhanced critical thinking skills, laboratory skills, and attitudes when compared with traditional teaching methods. Freedman (1997) has shown that ninth-grade physical science students with laboratory experiences demonstrated increased achievement and a more positive attitude toward science than those lacking such experiences. However, typical laboratory teaching will not result in the kind of inquiry recommended, so once again laboratory instruction is under the microscope. Just recently, the National Academies Press released the results of a major study titled America's Lab Report: Investigations in High School Science (Singer, Hilton, and Schwiengruber 2005) [Editor's note: See the Commentary on page 10. ] In order to enhance and revitalize laboratory teaching, one must recognize that not all laboratory activities have the same impact on learners. The cognitive component of the exercise is one of the most potent variables worth considering in predicting how a given activity will affect students and what learning it might foster. Schwab (1962) first proposed and Herron (1971) later modified a taxonomy of laboratory activities based on an appraisal of how much information the students have as the activity begins (Figure 1, p. 27). In a Level 0 laboratory, the teacher provides both the problem and method of solution. In addition, the answer is known before the laboratory because of prior knowledge held by students gleaned from the textbook or classroom. Level 1 activities are better but do little more than give students the opportunity to follow a recipe in cookbook fashion and verify some preexisting facts. Students have no authentic opportunities to make decisions about the nature of the procedure or choice of the problem. Only in Levels 2 and 3 are students really acting as scientists in the choices they make about procedures and problems. Considering the level of the laboratory can help teachers make informed choices about the impact that a particular activity might have on student learning and motivation, and help move activities toward higher levels of inquiry. Enhancing teaching and learning in the laboratory In additon to understanding the level of the lab, a review of the research literature reveals a number of suggestions that will enhance the overall student laboratory experience. Consider the following: Encouraging long-term investigations Scientists rarely conduct investigations in which the solution is assured within an hour or so. In contrast, students typically work in the laboratory with the expectation that an answer will be achieved quickly by simply following directions. To counter this view, students should have opportunities to engage in long-term investigations and explore phenomena that simply cannot be observed in one or two class periods. …