Computer-based interviewing systems could use models of respondent disfluency behaviors to predict a need for clarification of terms in survey questions. This study compares simulated speech interfaces that use two such models--a generic model and a stereotyped model that distinguishes between the speech of younger and older speakers--to several non-modeling speech interfaces in a task where respondents provided answers to survey questions from fictional scenarios. The modeling procedure found that the best predictor of conceptual misalignment was a critical "Goldilocks range" for response latency--that is, a response time that is neither too slow nor too fast--outside of which responses are more likely to be conceptually misaligned. Different Goldilocks ranges are effective for younger and older speakers. (Contains 2 tables, 4 figures, and 2 footnotes.)