Which type of questionnaire can have both open and closed questions?

A questionnaire that encompasses both open and closed questions is often referred to within the context of surveys. Surveys are designed to gather quantitative data through closed questions—these typically allow respondents to choose from a set of predetermined answers such as "yes/no" or rating scales. However, they can also include open-ended questions, which allow respondents to provide their own answers in their own words.

Using both types of questions in a survey can provide a richer dataset; closed questions lend themselves to easy statistical analysis, while open questions can reveal insights and nuances that might not be captured through structured options alone. This combination helps researchers gain a more comprehensive understanding of the respondents' perspectives.

Interviews often incorporate a conversational format, but they are not considered a type of questionnaire; instead, they are a method of data collection that can utilize a question-and-answer format similar to a questionnaire. Descriptive statistics and factor analysis are methods of analyzing data rather than types of questionnaires.