What Does It Mean to Be Intelligent?

Sometimes the unasked question reveals most. In exploring AI systems, and whether do or ever will achieve human-like intelligence, the unasked question is "What does it mean to be intelligent?" The answer is elusive since we have a sample set of precisely one species: humans. (Other species are certainly intelligent, but AI developers seek human-like intelligence so that humans may use the systems.) And, while we agree that humans are intelligent, we cannot describe what we mean, measure wha...