I assume that clue bats are used in the practice of retrophrenology?

OO is way more than a "tool" - it is a way of thinking and designing (checks and balances). If you think of it only as a tool, you have missed the whole point.

I wouldn't ask such a question to someone I was hiring to do database or Web development (for example). For the DB developer, I might ask "how do you find duplicate records in a database?", For the Web developer I might ask "How do you find the server address in JavaScript?".

I start with a phone interview and ask a few short answer questions like "What is a dead lock?" and "how can you guarantee that they don't happen?". Questions that are typically not taught in school are best. A lot don't get past this stage and it saves a lot of time. In the interview I give puzzles and watch how they solve them. Ask them to draw a state map for a common household appliance, or explain how they would solve a simple problem like debouncing a switch in software. Something that takes little setup time and can be solved in 10 - 15 minutes. I tailor the questions to the job duties to give the candidate an idea of the work they would be doing.