The choice of alternative answers is restricted to a predetermined list. The same introductory and concluding remarks are used. They are more scientific in nature than unstructured interviews. They introduce controls that permit the formulation of scientific generalizations. Limitation of the structured interviews - Collecting quantified, comparable data from all subjects in a uniform manner introduces a rigidity into the investigative procedures that may prevent the investigator from probing in sufficient depth.
Unstructured interviews are flexible.
They have few restrictions. If preplanned questions are asked, they are altered to suit the situation and subjects. Subjects are encouraged to express their thoughts freely. Only a few questions are asked to direct their answers. In some instances, the information is obtained in such a casual manner that the respondents are not aware they are being interviewed.