Forty-seven-year-old Jennifer has recently started tutoring students at the elementary school her own children attended many years ago. She enjoys being around the children and feels a great deal of satisfaction from her tutoring. Jennifer appears to be successfully resolving the crisis of
generativity versus self-absorption.

Which statement is a good description of a model? a) models are a description of nature based only on one or two variables. b) models are testable ideas but they are not very to most people. c) models are a description of nature that predicts more accurately than real events. d) models are an approximiation of a real system that omits all but most essential variables in a system.