Several years ago I learned MIT has some video learning courses you can watch without paying the tuition. And, as I’m kind of a nerd I decided to watch some of them. Which ones? A finance master-level class, solid state chemistry, principles of chemical science, and a few others.
I’ll admit I don’t comprehend everything said as I’m not paying full attention – so it’s just as if I were there – but I’m also not reading the book, studying, or going for a degree so it doesn’t really matter. In one of the classes a multiple choice question was asked, with equivalent answers:
Q: Which of these equations equal 1?
a. 2 – 1
b. 2 / 2
c. 0 + 1
d. 5 + 6 – 10
e. a, b, and c are correct
f. a, b, c, and d are correct
Of course the question was much harder, it is college. Results… 30% of the students said e and 58% of the students said f. The teacher felt that because e is a subset of f, that most of the students got it correct. But doesn’t selecting e imply that d is incorrect?
Following her logic, as a, b, c, and d are each correct and if you add up the responses to a, b, c, d, e, and f everyone technically got it correct; the only way to not get the question correct would be to either not answer it or writing in your own answer (um, not an option in multiple choice).
For multiple choice questions I was always told to choose the ‘most correct’ answer when compared to others. In my example a, b, c, and d are all as correct as each other, e is more correct because you recognize several are the correct answer (though, implying one is incorrect), and f is even more correct than e because you recognize all are correct.
Heck, when I took Calculus in college I had quizzes with five questions I had to take regularly. We never have ‘All of the Above’ as an option, just three to five options and sometimes a ‘None of the Above’. The catch? We had to select ALL answers which were correct. That means solving the problem, and then solving each answer to see if they were equivalent to the problem. If I got two of the three options correct I still missed the problem.
Take away: it’s OK to tell students they’re wrong if they don’t give a full answer.