Why use indoor labs?
Indoor Lab experiences have many potential benefits helping students of science master both content and process. The length of lab periods, relative to other kinds of formal learning environments contribute to benefits which include making science classes interactive, teaching with concrete examples, teaching students about the materials and practices of a discipline, and teaching students how science is done. These aims sometimes overlap and occasionally conflict with each other. One of the salient recommendations of the National Research Council publication "America's Lab Report" NRC, 2005 , was the need for lab designers and instructors to develop clear goals for lab experiences and to communicate these goals to students. (This report, a critical investigation of science laboratory experiences in high school settings, has much relevance for undergraduate lab experiences as well).
Because "the lab" is such a ubiquitous experience in science education, especially at the high school and college level, one can think of it as a "signature pedagogy" of science teaching, to use Lee S. Shulman's analysis in Pedagogies of Uncertainty (more info) . Like all such universal teaching methods, science labs can be more or less successful at their aims.
Making science classes interactive
In a lecture setting, especially a large lecture setting, students and instructors have to work at making learning student-centered and interactive. (But it can be done; see the Starting Point module interactive lectures for many good tips).
By contrast, a lab setting is naturally conducive to hands-on student experiences with the ideas and materials of science. Students can work together to draw cartoons of ocean environments in the Ordovician, 450 million years ago. They can examine biological specimens, create profiles across topographic maps, experiment with chemical assays, and create dynamic models of ecological systems using computer programs. Perhaps most important, they can talk about their ideas with instructors, lab assistants and fellow students. For many students, lab experiences not only reinforce material learned in lectures and through reading, but also create new understandings through students' active involvement with the concepts, procedures and materials. Many excellent science courses, in fact, are based on laboratory and workshop experiences rather than around lectures (see for example, the home page for workshop physics).
Using concrete examples
In education, teachers continually weigh the balance between an emphasis on the particular example and the general principles. In "How People Learn: Brain, Mind, Experience and School" NRC, 2000 , the authors point up the difficulties that students experience transferring skills and ideas when their knowledge is either "overcontextualized" or overly abstract (e.g. chapter 3, p. 53). One advantage of a lecture/lab format, then, is the opportunity to study in depth, during the lab period, a few concrete examples of the principles discussed in the lecture.
Introducing the materials and practices of a discipline
"Thinking like a biologist" (or geologist, or chemist, or any other discipline) means, in part, an acquaintance with the basic materials and tools used in that discipline. (And we would argue that learning to "think like a biologist" is an appropriate goal both for prospective biology majors and for students taking science courses out of general interest and to fulfill general education requirements). Thus, the main purpose of some labs will likely be practice with basic procedures such as titration, sample identification, dissection and others. It is common to criticize "cookbook labs," but when done for the purposes of learning and practicing correct procedures, detailed step-by-step instructions have as much place in the science lab as in the kitchen.
Teaching how science is done
A further reason to teach with labs is to give students experience working with scientific thought processes and methods, something likely to be useful both for the students who end up majoring in science and for those with another specialization who become informed citizens.
Extensive literature on the value of undergraduate research experiences in the sciences, for instance, points to the value of the whole intellectual process, from question asking, observation, testing, and presentation and the ownership students come to have, both of the process and their results. Although not all labs can replicate the open-ended nature of scientific research, they can "inculcate enthusiasm [and curiosity]" which is one of the main outcomes of undergraduate research experiences, according to Benefits of Undergraduate Research Experiences published in Science in 2007.
As practicing scientists know very well, the process of learning new things about the natural world is seldom straightforward and is not well-described in either the stereotypical "scientific method" nor in most published articles in scientific journals. (Journal articles, of course, have a distinct purpose of communicating methods, results, implications, and context, not of describing the research process, per se). As NRC, 2005 suggests, like the physical world itself, the process of doing science is infused with "complexity and ambiguity." Without authentic encounters with real data and the natural world itself (complicated data sets, measurements and observations they have made themselves), students run the risk of not understanding just how people come to know the material that is presented in science textbooks, in professional articles and in the press.
An additional consideration, well-expressed in Richard Feynman's famous 1974 commencement address at Cal Tech, Cargo Cult Science, is the potential that authentic lab experiences that require students to make sense of real data, develop and test hypotheses and then reflect on their results (or lack of results) will help students develop a habitual scientific integrity and honesty.
A few caveats
However, labs don't automatically carry these advantages. In recent years, good critiques of "standard" science labs have been offered by scholars of science education. One such critique is summarized by The worst way of learning science...is doing science. ( This site may be offline. ) . Derek Hodson points out that many science labs are written with a particular result in mind, and that students therefore spend their lab time trying to get "the result" the teacher wants, rather than understanding the process of science. If the experiment or the observations, don't work, these students may believe that they lack scientific skills. Such labs may be important for students to practice skills. But sometimes these labs are shortcuts for the work and imagination needed to craft a lab that really models the way science is done.
The key seems to be deciding on the goals of the lab and articulating these goals to the student. Hodson suggests involving students in the design of the labs, making labs open-ended and asking the students to reflect on both "successes" and "failures." He suggests that instructors think hard about whether to teach skills that few students may need (either later in the course, or in the rest of their life) and to prepare themselves and students thoroughly for the lab. Some of these considerations are fleshed out in the next section on Designing Indoor Labs.