I haven't had much time to write about problem solving, etc. lately, but something over at MyBiasedCoin caught my eye. The author asks whether it's a good idea to have a problem archive containing exam questions and solutions. (The exams would actually be drawn from the archive.) Several people, myself included, replied that it would be a good idea to have both problems and solutions. However, the author doesn't think including solutions is a good idea, because he feels that it's more important for students to think about CS theory problems the right way. If you've been following me over the past few years, you can imagine what my reaction to this was. (I don't disagree, but I still think making solutions available is helpful for students so they don't get stuck.) He hasn't replied yet, and perhaps he won't, but I hope some others respond. I'm particularly interested in hearing from people who can describe their "acquisition process" of CS theory – if they encountered any difficulties, how they worked through them, etc. Were they ever tested before working through their difficulties, and did they get lower grades than they'd hoped?