Interviews are a type of written questionnaire where the participant records their own responses.

Closed questions provide quantitative data which is difficult to analyse.

Questionnaires can contain both open questions and closed questions and participants record their own answers.

Questionnaires and interviews are often able to study large samples of people fairly easy and quickly.

Open questions provide qualitative data and although these type of questions are more difficult to analyse they can produce more in-depth responses relating to what the participant actually thinks rather than being restricted by categories.

If questionnaires are posted they usually have a high response rate.

Structured interviews can be very time consuming and difficult to carry out whereas unstructured interviews can restrict the respondents’ replies.

Social desirability bias can be a big problem with self report measures as participants often answer in a way to portray themselves in a good light.

The main weakness of self-report methods is that they do not allow participants to describe their own experiences.

Closed questions are questions which provide a limited choice