Being articulate has been equated with having a large vocabulary.
Conclusion (thus)
A large vocabulary is a hindrance to using language in a truly articulate way.
Evidence
People with large vocabularies have no incentive for, and tend not to engage in, the kind of creative linguistic self-expression required when no available words seem adequate.
Evaluate
The argument suggests that having a large vocabulary actually hinders articulation because people with extensive vocabularies lack the drive to creatively express themselves when words seem insufficient. The implicit idea is that truly articulate people are those who can creatively communicate despite limitations in vocabulary.
We need to identify what the argument assumes about being truly articulate, the New Concept in the Conclusion.
Goal
Look for an answer that links being truly articulate with the ability to creatively express oneself in situations where vocabulary alone isn’t enough.