Several important studies have emphasized the need for curricular change in undergraduate laboratories and lectures such that students can begin to understand the biological concepts amid torrents of seemingly unrelated facts (Howard Hughes Medical Institute, 1996; National Science Foundation, 1996; National Research Council, 2003). In response to these reports, it has been suggested that college-level laboratories be changed from "cookbook," isolated protocols to multiday, project-based procedures to help students understand the true nature of the scientific process and increase their overall understanding of the multistep, sequential nature of research (National Science Teachers Association, 2001).
Over the past 4 years our two-semester introductory biology laboratory series has been renovated to consist of multiweek project-based labs in genetics, biochemistry, and bioinformatics. The students no longer perform single-day experiments that conclude with predictable results meant to simply familiarize them with various techniques. They now design their own proteins and perform their own genetic and genomic screens. Our students still enter lab expecting to "learn how to use" pieces of equipment like thermocylcers or fluorimeters. Although these are part of our teaching objectives, during the first few years of these course changes our students seemed to lose sight of the relevance of the research and could not understand which integrated biological concepts governed their bench research. We remedied this problem by having our students write a brief "purpose statement" for each lab. The students are asked to explain the "who, what, where, when, why, and how" of the science of the overall laboratory procedure in one or two sentences based on their reading of the protocol and background in advance of the laboratory session. The lab TA goes over the purpose before the students begin their experiments, stressing the "why" of the protocol in these discussions.
We have found that assigning scientific "purposes" helps our students in many aspects of the lab course. At the beginning of the class, we receive purposes for the initial labs that include such statements as "to understand how to perform SDS-PAGE" which transition into "purifying and characterizing mutant crystallin protein." Students begin to understand and focus on the concepts behind the labs. In addition, by emphasizing the "why" behind each week's experiment, the students see that our several-week experiments have a single scientific goal. …