John Needs a Paperweight to Keep Open a Book from Which

Multiple Choice

John needs a paperweight to keep open a book from which he is making notes. He does not own a paperweight. There is small red building-brick keeping his door open that would be perfect as a weight, but when John looks at it, he doesn't think of it as a paperweight. In this case, John has fallen prey to

A) item compensation.
B) a very bad heuristic.
C) algorithmic failure.
D) functional fixedness.