My equipment doesn’t work…

We’re three weeks into our ‘B’ semester here. One of the papers I’m teaching (just on the fringes of) is our main first year physics paper. When I say ‘on the fringes of’, it means I’m supervising one laboratory session a week. It’s good to keep in contact with what’s going on at first year – all my other teaching is 2nd or 3rd year or graduate level.

One thing that seems to be happening is that, every year, the incoming cohort of students is less confident in their use of equipment in their physics lab classes. Is this because they are doing less and less practical work at school? One thing for sure is that students can find even the most simple piece of equipment a real stumbling block.

The main purpose of the laboratory classes is to give students the chance to experience the physics that is talked about by lecturers for themselves, and thus give them a practical learning opportunity. It’s one thing to hear a lecturer talk about the force on a current carrying wire in a magnetic field, which can be pretty abstract  – it’s another to measure the force for yourself and verify that indeed the force is proportional to the current.

However, these opportunities are often clouded by unfamiliar and frightening equipment. What often happens is that the student spends the laboratory trying to figure out how to use the equipment, rather than looking at the physics the experiment is designed to illustrate. The chance for meaningful learning is thus rather diminished.

From my observations I can see two ways that this occurs. First, is the obvious "I don’t understand the equipment". "Which wire do I connect to which terminal?", "Which mirror do I need to use for part A", and so forth. The focus of the student is on the equipment, not the science. The second way is blind trust in the equipment. A student tries to take a reading of current and connects the multimeter in parallel with the component, and then assumes it must be right. Having a digital display rather than analogue seems to up someone’s confidence in the equipment. If it’s hi-tec, it has to be right (even when it is used incorrectly).

It’s a tricky balance to get right. On the one hand, a student needs to use experimental equipment correctly, but on the other we don’t want our lab classes simply to be about learning to use pieces of equipment that most students will never come across again. In fact, at second year electronics, we’ve now got a module on common pieces of lab equipment, in which the focus is to learn how to use multimeters, signal generators, oscilloscopes etc correctly.

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