Surveys are useful for getting a great deal of specific information. Surveys can contain open-ended questions (e.g., “In which city and state were you born? ____________”) or closed-ended, where the respondent is asked to select answers from a brief list (e.g., “__Male ___ Female.” Open ended questions have the advantage that the respondent is not limited to the options listed, and that the respondent is not being influenced by seeing a list of responses. However, open-ended questions are often skipped by respondents, and coding them can be quite a challenge. In general, for surveys to yield meaningful responses, sample sizes of over 100 are usually required because precision is essential. For example, if a market share of twenty percent would result in a loss while thirty percent would be profitable, a confidence interval of 20-35% is too wide to be useful.