An answer to an ID question can be very short, it can be the title of the movie and a link to imdb or wiki.
These sorts of answers, though, are very low quality. They might serve to answer that particular question, but those that stumble upon the question in the future might be looking for a different, yet similar, movie/tv/etc.
What if, instead of just providing the title or episode number or whatever, we give details on WHY the movie matches. What elements does the answer match, what elements DON'T match. How did we come to that conclusion? What websites did we look at to find the answer? What did we search for on our journey to the answer?
We can gleam a lot of insight into how correct an answer might be when provided this information. We can also teach future readers how to answer these questions for themselves.
So please, when answering an ID question, provide some more detail. It'll help everyone out.