Teaching Laboratory ClassesWritten by Alan Dickman, Ersted Award winning teacher, 301 Pacific Hall (346-2549), firstname.lastname@example.org, on September 14, 1994
You can do almost anything in a laboratory setting that can be done in other class settings including discussions and giving lectures. But because the reverse is not true, and most of us are not fortunate enough to be able to hold all class sessions in the lab, the real question is, how can we make most efficient use of laboratory time? This requires that you know what you want to accomplish in the laboratory, and this will depend on who your students are, what kind of class you teach, and your constraints (time, materials, equipment).
Here are some things that I think are often quite valuable and that can be accomplished better in a laboratory setting than in a large lecture. I will briefly explain why I do these, and give a few examples from some of my courses.
Get to know your students and create a safe and friendly atmosphere.
The better you know students the easier it will be for you to help them learn and the more they will feel a part of the class. We take pictures of students on the first day and either write their names directly on the photos, or use a portrait camera and take their picture while they are holding a name tag. If feasible, encourage students to bring goodies to share with the class. If there are concerns about personal safety (toxic materials) or care of valuable equipment (computers) see if a clean bench can be established, or if a nearby room is available for such activities either during or before the lab.
Get students to work in small groups with other students.
Explaining a concept to someone else is a good way to learn it. You can build these kind of exercises into lab activities, either formally or informally. We intentionally put 8 to 12 computers into a lab of 24 students and routinely ask them to make predictions about what will happen in a given situation, and then to compare their answer with another student. These interchanges can be very valuable to students.
Motivate students with hand-on examples.
In biology, we are able to take advantage of students natural interest in living things to spark their enthusiasm for more abstract concepts. While these kinds of opportunities are not inherently investigative, they can be made to be so. For example, we look at soil arthropods from a variety of forest types, and ask students to make a hypothesis about the differences they observe in abundance and diversity.
Allow students to be creative.
Scientists agree that science is a creative activity but many lab classes have students work through a list of predetermined procedures. When possible, have students help design the protocol. In other words, have them be real scientists. For example, after introducing students to soil fauna, and getting them to think about differences between sites, we have them (working in small groups) design an experiment to test one of their hypotheses. Then the class discusses these experiments, and chooses one (after modifications) to actually carry out in another lab period.
Help students to understand the significance of the activity.
Too often, students will follow the instructions in a lab manual without knowing what they are doing, or why they are doing it. If the activities are already designed for you, go around to students and ask them to explain what they are doing, and why they are doing it. (They can also do this with each other, but it is often very informative for you, as an instructor, to find out what students are thinking). Try to lessen the tendency of students to get through the lab to obtain an answer or result, without knowing what it means. If you are writing or designing activities, you can build this kind of questioning into the lab. If your activities are already set, you can get students accustomed to asking themselves these kinds of questions if you do it regularly. And, of course, if you write exams for the lab, you can ask these questions on exams, too.
Challenge students to construct their own models and to investigate them.
Frequently it is useful to use manipulatives to teach abstract concepts (like many people, we use pipe cleaners to stimulate chromosome in the teaching of nuclear division). These can be very useful activities, but sometimes students are confused by the symbols used. A colleague of mine (Peter Wetherwax) gives students appropriate building materials for a model of protein synthesis (colored beads, paper strips, etc.) and has students determine, for themselves, what each part of the model represents in the real cell. This helps minimize the tendency of students to follow instructions without knowing what is happening. Students can even build mental models and share them. For example, how is a cell analogous to a city? It is also helpful to have students criticize their own models, pointing out where the analogy works and where it doesn't (and why).
Familiarize students with techniques and laboratory tools.
If this is a goal of the course, find ways to make the learning of new techniques and unfamiliar equipment non-intimidating. Take time to explicitly instruct students on how to use tools. It's easy for us to forget hoe foreign things like microscopes can be to the uninitiated. We prepare handouts on microscopes to be left in the lab so that students can refer to them whenever needed.
A given course might not include all of these activities, but many of them do work synergistically. For example, the better students get to know one another, the more likely they are to work cooperatively, and the more common it is for creative ideas to catch-on and spread throughout the group. Finally, as in all teaching, be creative yourself. Try new things. Share ideas with colleagues; see how others teach similar courses or concepts. Just like your students, work in small groups and ask yourself why you are doing what you are doing. And don't forget to have fun.