Structured interviews are standardized, much like tests. They have pre-designated questions, sequence, even scoring. The interviewer is directive, steering the conversations in predetermined directions. Standardization facilitates comparison of individuals by providing a common focus and metric. Research suggests structure can improve reliability and validity.
Unstructured interviews have a free flowing, spontaneous quality.
The interviewer is relatively nondirective, following the interviewee's lead. Rapport Interviews are typically more disclosing, honest, and responsive when their relationship with the interviewer is warm and comfortable. Interviewers will therefore make attempts to be overtly pleasant, respectful, interested, and nonjudgemental. Interactive Interviews are interaction between two people, effected by both. Interview outcomes thus depend on characteristics of both participants and their interaction.