Stager, J. C. 1994. The Journal of College Science Teaching, November.
I would like to introduce an exciting approach to biology lab instruction that plunges first-year students into the vibrant world of original research. It gives students practice in critical thinking, experimental design and execution, public communication and writing, and group investigation. I also believe this approach would work well in almost any scientific field and at any academic level.
Two weeks into the fall semester of 1991, it struck me that the "standard" biology labs we were using in second semester biology did little to spark the thrill of scientific investigation. How could I share with students the excitement I have when I probe the waters of a lake, or ponder the ecology of the Adirondacks where I live and teach?
The answer came in a flash: just do it! I decided, on the spot, to let the students plan and conduct a scientific in vestigation on any topic they chose, so long as it was both interesting and "biological" in nature. The students were incredulous at first, not sure that I meant they could really focus their research on whatever interested them. We began by searching the nearby woods for mysteries to investigate, and followed up on every question that arose with direct observation and experimentation. This led to a very successful semester of student-generated research projects that culminated in a symposium and a growing file of research reports. It has now evolved into the standard method of teaching second-semester biology lab here at Paul Smith's College. What follows is an overview of the investigative lab curriculum.
During the first weed, we relearn how to ask questions. Giving voice and credence to questions as they arise from the subconscious is foreign to traditional schooling, and it often takes practice to reawaken one's innate curiosity about the world.
Each student writes three questions, of any sort, on scrap paper and hands them in anonymously. I read a dozen of them aloud to the class and lead a group discussion of the testability of various kinds of questions. It soon becomes obvious that some questions are easier to answer than others, depending on how they are worded. For example, "Why do birds migrate?" is tougher to tackle than "When do birds migrate northwards?" or, simpler still, "When will the first robin arrive on campus this spring?" In this way students begin to appreciate the importance of careful wording in planning and communicating scientific studies.
Each student then makes a second list of three questions that could be answered by class investigation within half an hour. I present several to the class, they choose one to investigate, and then split into three subgroups.
Their only instructions are to gather data that will address the question (e.g. "Is the ratio of heartbeat to breathing rate constant among college students?") and present their results to the rest of the class within half an hour. During the informal oral presentations and discussions that follow, students notice that each group has taken a different approach to the question, and has come up with somewhat different conclusions. Here students start to understand the effects of sample size and experimental design on outcomes, the dynamics of group work, and the value of peer review in the evaluation of research results.
The next three weeks are dedicated to the statistical treatment of data, which are collected and used by subgroups during the lab periods. Each session begins with a brief lecture in which the need for a particular statistic is demonstrated. Only those concepts that are to be used in class that day are introduced, and all calculations are first conducted from an instructional handout, as a class, to minimize math anxiety. An excellent, readable source of instruction in these statistical tests is Handbook of Biological Investigation (H.W. Ambrose and K.P. Ambrose, 1987).
After the introductory lecture, subgroups are formed, asked for questions that would yield data relevant to the statistic of the day, and turned loose for brief investigations followed by group presentations and discussions. For these exercises, students are required to word their questions as hypotheses, and to "reject" or "fail to reject" them on the basis of their data. The weekly homework assignment is for each student to conduct a half-hour study of their own design, using the statistic of the week, and to hand in a one-page report on their research findings.
We begin with mean, range, and standard deviation, showing how wildly different data sets can have the same means, and how additional information (e.g. ranges and standard deviations) is often necessary to understand a data set. Subgroup projects are often humorous or creative, and have dealt with such diverse topics as the thickness of a fingernail, the spread of a raindrop on impact, and the width of a clover leaf.
As the students come up with these projects, they often choose to compare the means of two data sets, such as the lengths of writing arms versus non writing arms, or the abundance of moss on the north versus south sides of a tree. This leads naturally to an awareness of the need for a way to tell whether or not two apparently different means are significantly different. I use one of these student data sets to introduce the t-test the following week. Students are often amazed to find that, for example, the mean height of the males in class may not be significantly different from that of the females, even though the means differ by an inch or more. The chi-square test is presented as a way to tell whether objects are scattered randomly over a region or clumped in some way, which leads to additional testable questions about why they are distributed as they are. Student-generated studies have included the distribution of birthdays throughout the year, of towns in the Adirondack Park, and of zoo plankton in a local lake.
The next two weeks expose students to scientific literature. We examine the journals in the library, and learn to locate papers on topics of interest. Each student chooses one paper to present orally to the class the following week, in a mock symposium. This gives students an overview of kinds of research done by professional scientists, exposure to scientific writing and speaking styles, practice evaluating research through class discussion, and more experience in public speaking. It also serves as a dress rehearsal for the symposium at the end of the semester, in which they will present the results of their own research to their peers. It is especially exciting when students find papers that cover subjects that have appeared in our own class investigations!
The remainder of the course is devoted to independent research, using skills developed over the previous six weeks. Each student (or group of up to three) submits a written research proposal for approval. The only criteria are that the project must be biological in scope, must yield a data set suitable for statistical analysis, and must take three to four weeks to complete. Throughout the semester, students are reminded of the need to come up with a project, and are provided with a list of suggested topics and a file of reports of previous biology lab projects in the library. Past topics have ranged from a biochemical analysis of hot sauces to the food preferences of local birds. Many projects are continuations of the short studies conducted in previous weeks, such as the study of the distri bution of zoo plankton in a lake, or the size of the "personal spaces" of men and women.
For three weeks, students check in at the start of each lab session, give a brief progress report, and go about their work. The fourth week is devoted primarily to the preparation of visual aids. The personal involvement students have in these projects is striking; most eagerly work overtime on their investigations, in stark contrast to the "hurry through and leave" attitude often apparent in more traditional labs. Many students are driven by the excitement of knowing that their work will be referred to by others, as many lines of research are continued by future generations of students. Often the results are of interest outside the college community, such as studies of the toxicity of rotenone (used in local lake reclamations) on aquatic invertebrates, or the history of housing development on a local lake suffering from cultural eutrophication.
The final student symposium follows the format of professional meetings, and is open to the campus community. Each presenter is allotted 10 minutes, with five minutes for questions and answers from the audience. Members of earlier biology classes often attend to help critique the projects, and to see how their own work has been carried on. Rough drafts of research reports are due during the symposium as well, and comments from the audience are noted for inclusion in the edited final draft, which is due the following week.
My grading system for this laboratory is as follows: attendance (10%), homework and class activities (30%), journal presentation (15%), research proposal on time (5%), student sym posium (20%), final written research report (20%).
Students are generally very conscientious about completing their assignments to the best of their ability. I attribute this, in part, to the subtle pressure that arises when one's work is presented to one's classmates each week for peer review. I also believe that students are often more motivated when they are allowed to follow their own natural curiosity in a hands-on manner.
One might worry that, in a relatively unstructured course such as this, students would not be exposed to a full array of biological principles and techniques. My main arguments against this line of reasoning are that the students can be exposed to plenty of these principles and techniques in their first semester biology lab and in lecture, that this kind of curriculum can show students how to think like scientists as well as to use equipment, and that students (and faculty) in this course are exposed to a diversity of student-generated topics that the instructor might never consider.
A case in point is one in which a student asked in passing if it was true that cold water heats up faster than hot water. "Of course not," some of us replied. In a normal course, we would simply have passed right along to the planned exercises of the day. Instead our research subgroups tested the idea and found, to their amazement, that cold water actually does warm faster than hot water. Simply by following the curiosity of the moment, we earned about the physics of heat transfer (with the help of a physicist down the hall), the strength of controlled and repeatable testing in convincing skeptics, and the value of the scientific method in learning about the world we think we know so well.
Another point in favor of this approach to introductory biology lab is that it can be virtually cost-free. My only expenses are the photocopying of handouts and the occasional replacement of lab equipment that is normally on hand in the room (e.g., meter sticks, microscopes, plankton nets, etc.). It is surprisingly easy, with practice, to find questions worthy of investigation in the outdoors or on campus that don't require expensive tools or dangerous reagents.
Finally, I'd like to suggest that anybody with a sense of adventure and a willingness to say to students, "I don't know, let's find out," can turn their introductory lab course into a place of discovery. You don't need release time if you just invent the course with your students during class time. You don't need to wait around for a grant to fund your plans. The reform of science education in our schools does not need huge infusions of money as much as it needs a healthy dose of creativity and enthusiasm. If you really want to improve the state of science education in America, then my advice is, just do it!