DEPARTMENT OF PHYSICS, OREGON STATE UNIVERSITY
In the introductory courses, the lab equipment, student responsibilities and TA responsibilities vary greatly. In some labs, the students take the measurements, analyze and record the data by hand, while in others computers acquire, analyze and store the data. The latter are called MBL (Microcomputer-Based Laboratories). In some cases, the students are required to read the lab instructions and part of the textbook, and complete a pre-lab assignment before the lab begins. If they don't, then they aren't allowed to do the lab. In others, the students are required only to read the lab instructions and part of the textbook. In some courses, the TAs must check the students' work several times during the lab, and once at the end. The students can't continue the lab procedures until they have had their work checked. In others the TAs only check the students' work after they have completed the lab, unless they explicitly ask to have their work checked earlier. In the Modern Physics lab, the students may even be working on different experiments.
A typical lab:
The TAs are also responsible for guiding the students through the laboratory exercises, explaining how to use the equipment, pointing out dangers and pitfalls, making sure that the students learn as much as possible. The Socratic Method helps students learn the most. It involves asking directed questions instead of giving answers. This is a very subtle skill, and takes lots of practice.
For example, suppose a student has a circuit with two identical light bulbs in series with one another and in parallel with a third identical one, all in parallel with a big battery. The student asks which bulb will glow most brightly. Instead of answering directly, ask the student how much current will flow through each light bulb. If the student claims that current is being used up, then switch to an analogy with a water pump and three waterfalls, and ask the student if the water gets used up as it falls.
It is important to get the students to identify their misconceptions. If you simply tell the students the correct answers, they will think that they understand, and then proceed to make the same mistakes all over again. It's OK to leave students to ponder over a point while you assist other students, but be sure to return to resume the discussion, or you will leave them feeling abandoned and frustrated.
Sometimes everyone seems to have the same problem. In this case, politely interrupt the class and discuss the problem with everyone at once. This will save time for everyone.
You may begin each lab with a short introduction followed by a discussion where the students ask questions.
Preparation and general guidance:
Prepare adequately for each lab. Work through the lab yourself, preferably with the other TAs. Make sure you know how the equipment works and where the potential problems are. Arrive a few minutes before each lab is scheduled to begin. Return the student's work at the beginning of each lab. Write legibly on the board and speak loudly and clearly so that everyone can hear. Create a syllabus and distribute copies at the beginning of the first lab. Learn the names of your students as quickly as possible.
Evaluation of the students' performances varies with the course and instructor. Be sure your instructor has made grading policies clear to you. Be absolutely certain of the policy before your first lab, as you might be grilled on the minutest details of the grading scheme.
Feedback:
The course instructors would appreciate it very much if you would tell them how the labs could be improved. Let them know what works and what doesn't. Providing feedback in a written form works best.