What are Concepts? (Part 1)

Amongst my many pet peeves about Intro Psych textbooks is how they handle 'concepts.' It is not so much that they use the term particularly badly, it is that they do not provide any context (i.e., this is a problem even if we put aside the need to redesign Intro Psych more broadly). In particular, I don't see how 'concepts' make any sense without at least some discussion of 'percepts' - the two