Multiple-choice in Physics & Chemistry

In my Physics and Chemistry courses, the tests are all multiple-choice. And they're not like the multiple-choice I'm used to from High School, Biology say, when if you know the work, you can see the answer right away and just check it off.

No, these are different. Like do a normal question, that might take a few minutes and use up most of a page of calculation. Then look at the alternatives given, and hope that your answer corresponds to one of them. Scary when it doesn't. Do I look over my work to see if I can see a mistake? Do I re-do the thing and hope it comes out to one of the answers that at least could be right? Or maybe skip it and try the next one, then come back to it if there's time? There's a technique to this, and I haven't caught on to it yet.

I'm not used to it. There are no marks for part answers. You can get the question basically right, but make just one mistake (maybe a stupid mistake), and then you get no credit at all for what you've done. Just the same as someone who's goofed off and done, basically, none of the work at all, and who therefore really deserves to get the same zero for the question that I got just because of one stupid mistake.

And I soon found out the hard way that the prof who set the question knows the kinds of mistakes people are likely to make, and puts them in for the alternatives; like maybe (c) is the right answer, but he puts answers that people are likely to come up with when they've made the mistakes he knows about as (a), (b), and (d). They're diabolical, some of these guys.

There are over a thousand people in these courses, so I can see why they do it. But then sometimes I think that they get over a thousand lots of fees too, so they should have us write out proper answers and pay people to mark them. But I guess there'd have to be instructions and maybe even meetings for the people who marked the questions to make sure all of them marked in the same way. It could get complicated.

One good thing, though, is this: we all get our results pretty well right away, with all the stats about medians and things. We can see how well we've done compared with everyone else. And they give us the right answers for the ones we got wrong, so we can take it away and see if we can figure out the mistake we made. That's useful. It would be even more useful if we ever had the time to actually do any of it.

But then time ... that's the topic for another story. Or perhaps six more stories. Sorry, I'm short of time so you'll have to get someone else to write them for you.