Laboratories set science apart from many subjects. At their worst, labs are viewed as costly, time-consuming, “cookbook” approaches to experimentation. When taught well, however, laboratories can provide a unique experience for students to think like professional scientists, develop skills and techniques important to their discipline, and collaborate with peers.
During laboratories, instructors get to teach with concrete props. While props engage and involve students, they can also distract from the conceptual goals of the class. Clarify expectations early (e.g., “At the end of class the student should know how to set up and operate a ______”) and provide adequate opportunities for students to practice using equipment. Ensuring that students possess necessary technical skills will better allow instructors and students to focus on learning the process of science.
Effective laboratories simulate the process of scientific inquiry. One way to achieve this goal is to allow students to design and conduct individual experimental investigations as part of the course. Students can then experience the excitement that often accompanies scientific discovery, as well as practice critical thinking skills necessary for planning, executing, analyzing and interpreting a scientific study. Prepare students to interpret unexpected results by coordinating practical exercises with material taught in the lecture. If students have a solid foundation in the scientific principles that drive the experimental questions, they’ll have a context in which to interpret results, thereby linking and reinforcing concepts covered in both lab and lecture.
Laboratories provide an opportunity for—and necessitate—teacher involvement. Effective supervision will facilitate inquiry, allow instructors to recognize students having difficulties with fundamental concepts, and provide students with crucial links between data and scientific concepts as they analyze their data.
Helen Alexander and Cathy Collins, KU ecology and evolutionary biology, suggest the following:
“Laboratory courses are typically designed to give students hands-on experience in science. Students often like the interaction and small group activities. However, they can get frustrated by long class periods and a sense of chaos if laboratory exercises are poorly designed. Teachers, in turn, enjoy the opportunity to get to know students and teach experientially, but find that planning the course, carrying out the exercises, and grading the reports take much more time than the typical lecture course. Based on our experience, several factors can improve the experience for teachers and students:
- “Clarify the link between laboratory exercises and big picture course concepts. During the planning phase, identifying links will help instructors choose exercises that truly accomplish learning goals; while teaching, such links provide students a context in which to connect isolated laboratory lessons to broader course topics.
- “Time spent on logistics and advance planning are key to successful laboratory exercises. Laboratory classes can be derailed if procedures or equipment don’t work or supplies are missing. Because students will often have different backgrounds in the course content and other skills (e.g. use of statistics software, microcentrifuge, etc.), preparation of ‘how to’ handouts saves time for students and reduces frustration.
- “Ideally, laboratory classes should teach students to think like scientists by allowing them to pose questions, formulate hypotheses, and design and conduct studies that address their hypotheses. Too often students look for a correct answer because laboratories are structured to obtain specific results. Allow for some portion of the lab course to be devoted to studies that are not cookbook in nature, then take advantage of the small group format to facilitate discussion of unexpected results.
- “Students need rapid feedback, both in terms of answers to questions on laboratory procedures and on laboratory write-ups. Teachers, however, can be overwhelmed by the workload of reading many papers. We can reduce frustration on both sides by breaking assignments into parts that are due on different dates and providing examples of the type of products we expect.”
McKeachie (2002) outlines four different styles of conducting laboratory instruction.
Expository Instruction – Students verify preordained results, develop manipulation skills and follow exactly prescribed directions. This style is useful for larger classes as it requires little instructor engagement, though there is a possibility that almost no meaningful learning takes place.
Inquiry Instruction – Students mimic the process of constructing knowledge by formulating their own problem based on the information at hand. There are no preordained outcomes with this method, though concealing the details of the solution from students can be difficult.
Discovery Instruction – Also called “guided inquiry,” this style starts with a preordained outcome. The students are not told the outcome; rather, the instructor guides students toward the outcome through discussion and evaluation of proposed experimentation. Discovery instruction allows students to own their learning and often results in deeper understanding.
Problem-based Learning – Instructors craft a case study with selected evidence, and students uncover the lesson the instructor intends to teach. In this context, students learn to create their own questions with a strong foregrounding by the instructor.
McKeachie, W.J. (2002). McKeachie’s teaching tips: Strategies, research and theory for college and university teachers (11th ed.) Boston: Houghton Mifflin.