In a questionnaire or structured interview it is possible to ask open questions or closed questions. Closed questions are those with a limited number of possible responses, often "yes" or "no". Closed questions help to make data easier to analyse and to make it more reliable. This is because closed questions produce quantitative data. However, restricting responses can impact validity. To try to overcome this, sociologists often give more possible responses to closed questions, such as ranking possible responses or indicating how far they agree with a statement (Likert scale). It is also possible to mix closed questions with an open "other (please specify)" option.