Lawyers famously say, “Never ask a question unless you already know the answer.”
I’m supplementing a third-party application we recently installed that administers quizzes online. It’s nothing revolutionary – students take a quiz, and it’s graded automatically. I just need to generate a new report that includes the already-calculated quiz grades, so I’m studying the database.
I started with the table results_answers which lists students’ individual answers, and includes a column called result_answer_iscorrect. Excellent! This must show a 1 if the answer is correct, or a 0 if it’s not. Let’s just ask the database to make sure:
[bobbojones@production xxx] > SELECT result_answer_iscorrect, COUNT(1)
FROM results_answers
GROUP BY result_answer_iscorrect;
+-------------------------+----------+
| result_answer_iscorrect | count(1) |
+-------------------------+----------+
| 0 | 425 |
| 2 | 18986 |
| 3 | 5259 |
+-------------------------+----------+
3 rows in set (0.15 sec)
Blërg! (There aren’t any ones, but there are twos and threes.)
I knew I shouldn’t have asked the question.
I suppose you could infer the meaning of those values based on the quality of the students taking the quizzes.
So maybe 2 means correct, 3 means incorrect, and zero means didn’t answer or something.
Now if the students are particular dim bulbs,
0 = correct
2 = incorrect
3 = all of the above
And if they’re really wits of nit, you had it right from the start:
0 = incorrect
1 = correct
2 = didn’t answer
3 = what was the question?