Past research has shown that vague or ambiguous categorical concepts can be clarified through the use of definitions, instructions, or examples, but respondents do not necessarily attend to these clarifications. The present research investigates whether the presence of instructions or their placement modifies respondents’ concepts so that they are better aligned with research objectives. Eight questions, modeled after major federal surveys, were administered in one panel of a twelve-month Web panel survey to a nationally representative multistage area probability sample of addresses in the United States (n = 913 completed interviews). There is some evidence to suggest that, as predicted, respondents anticipate the end of a question and are more likely to ignore instructions placed after a question than before. Respondents answer more quickly when instructions come after the question, suggesting that they spend less time processing the instructions in this position, and their answers appear to be less consistent with research intentions. As predicted, implementing instructions in a series of questions is more effective than the other approaches examined.