Ideally, questions should capture constructs they were created to capture. However, it is important to know if questions are not capturing intended constructs. Understanding constructs that questions are capturing allows survey managers to modify questions, and allows data users to understand the potential range of constructs that may have been captured in the data. Both of these measures increase the data validity.

Respondents' interpretations of a question may differ depending on their social experiences and demographic factors. For example, respondents with different education levels might interpret or comprehend question terminology differently.

There are many possible reasons why respondents might have difficulty answering a question. Question evaluation can help to shed light on this process.