When is it better to let the student think it out?

When a student asks a question, how should a teacher respond? Should a complete answer be given? Should the student be left to puzzle it out on their own? Should the teacher provide some hints but leave the student to figure out the rest?

This question was brought to mind in a recent chain of emails on the SIGCSE mailing lists regarding plagiarism. The conversation suggested that part of the problem with plagiarism in school is the misdirection we give students. What we want to know is the process they used to think, the mental models they have and how they use them. But what we ask them to do is present an answer to a question or a solution to a problem. Thus, what to us is the very different processes of finding assistance in understanding problems and approaches and finding solutions and answers ready to hand in are, to the student, often almost indistinguishable. Both are getting help getting the task done.

How do you know when a question is a “‍help me understand‍” question rather than a “‍help me perform‍” question? Can you answer “‍help me perform‍” questions in a way that also helps understanding? More interestingly, can you answer “‍help me understand‍” questions in a way that is less beneficial to understanding than is not answering?

Often in CS1 courses students ask questions of the form “‍what happens if you write X instead?‍” The correct answer, of course, is “‍try it and see‍”—correct because it teaches the students to answer their own questions. But after they try they often ask “‍why does Y happen when I write X?‍” How to answer these questions is much harder to judge. If the students think it through and come up with a why on their own, they learn a great deal. But if they think it through and come up with the wrong answer they get in a jam. And if they think it through and get frustrated, their interest and focus drop.

I suspect which questions to answer how depends on the individual students doing the asking. That, of course, is at loggerheads with the classroom model: different students would benefit from different answers. What is the correct balance for the classroom as a whole?