Purpose Driven Labs

Consider the traditional handout provided in a physics lab. It might be a handout found in a textbook's Laboratory Manual or it could be a handout drafted by a teacher. The handout typically provides students with a purpose, a procedure, diagrams, data tables, a conclusion section, follow-up questions, etc. The result of the handout is that students are typically guided through a lab experience by the structure which is provided within the handout. The handout - with its procedures, structured data tables and follow-up questions - becomes the guide to the student. And often, it is a very good guide.

The presence of the handout in the hands of the student insures in most instances a relatively effective learning experience. So why would any physics teacher wish to discard a lab handout which insures a relatively effective learning experience? The answer is simple. The doing of labs in a science classroom is not simply about the learning of scientific concepts. A lab handout or collection of handouts which assist students in learning a particular concept or collection of concepts does not necessarily constitute good curriculum. It simply has value in leading students to answers which are found in the textbook. A good lab handout does very little to demonstrate to students the nature of science as a laboratory activity.

Labs are done in part because it is in the lab that the answers to our scientific inquiries are found; this is the nature of science as a professional practice. A science education should be about more than what the answers to those questions are; it should be about how those answers are found. Labs are not just about learning a science concept; labs are about doing science. A science course which has an effective lab program is a course which engages students in doing authentic lab investigations - investigations which challenge students to answer unique and interesting scientific questions in a variety of ways. Students should learn how to conduct an investigation, not just what the answer is. The primary value of the lab is in the act of investigating, not simply in the result of the investigation.

In a lab, a science student should learn about how scientists work - how they control variables, make alterations of procedure, repeat measurements, organize data, analyze data, compare data with other scientists, display the results and report the findings. These practices of scientists should be practiced by science students. And as students implement these practices, they should be learning to make decisions about how to control variables, how and when to make an alteration in a procedure, when to repeat measurements, how to organize data, how to analyze collections of data generated by multiple scientists, and how to display and report on the findings. Decisions about these practices should be made by the student, and not by the procedural directions provided by a laboratory manual. When students are left with the responsibility of making these decisions, they are learning how to conduct a scientific investigation in a manner similar to a scientist. They are participating in the practices of a scientist.

Even a good lab handout tends to distract a student from the question. The procedure, the data table and the other structures within the handout become front and center. The student focuses on making progress through the handout and the question moves to the background and accidentally gets lost or forgotten. Students' tendency to do science becomes minimized on their radar screen; the completion of a handout becomes maximized; and the processes of scientific inquiry becomes jeopardized.

When a student walks into the lab, the question should be front and center. If laboratory work is about determining the answer to an inquisitive question, then the question should always be the focus. By withdrawing the lab handout and providing students with a well-written purpose and a blank page in a lab notebook, the question becomes front and center. Of course, the pre-Lab session might include a clarification of that purpose or a short description of the measuring tools or apparatus (if students are unfamiliar with them) or maybe even some suggestions and warnings about what not to do and probably a note of safety. But when students embark to the lab, it is the Purpose which they are left with. And at the heart of the Purpose is a question or an inquiry. And as students pursue the question, they are more likely to become engaged in inquiry-driven lab.

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