What are unstructured and structured interviews?
Interviews can either be structured or unstructured, and the main issues which have to be considered when discussing them are reliability and validity. The unstructured interview is an interviewing technique whereby questions are not specifically limited and set, and the conversation can flow freely. The questions asked in an unstructured interview can change depending on how each individual responds, and questions asked are usually open-ended. During an unstructured interview several topics can be discussed. In these cases, the interviewer usually engages in lengthy explanations of the job, and asks questions which are not necessarily predetermined by the interviewer. After the interview, errors in the information gained from the applicant can occur and the final choice maybe determined based on unclear impressions. However, unstructured interviews can help gain information which was not planned and can be helpful in areas which need more explanation.
Previous research has shown that unstructured interviews have low predictive validities. For example, Hunter and Hunter (1984) found the reasons as to why predictive validity was low during the selection process is because the questions asked where not really related to the job or were unable to be scored reliably. Interviewers can also base their information on appearance, instead of performance on the job. Similarity influences also occur (e.g. tendency to hire someone who is similar to the interviewer). Another problem with unstructured interviews is that it can be time consuming and because the information gathered from all the respondents is different, it is difficult to have a base for comparison, which affects reliability and validity.
Structured interviews involve questions which are set out and followed thoroughly. Each candidate is presented with the same questions and this ensures that each respondent has had the opportunity to respond to each question. Structured interviews have higher predictive validity. Structured interviews are better at predicting job performance if they are appropriately and thoroughly based on job analysis and trained interviewers are used. Structured interviews assume that intentions and actual behaviors are strongly linked. Structured interviews can also involve multiple interviewers and use well-defined rating scales with specific rating procedures. Asking candidates the same questions (standardized questioning) and taking down relevant notes during the process can also improve validity and reliability of the interview.
PsyAsia International's registered psychologists provide professional training workshops in Behavior-based Interviewing. The workshops take delegates through the entire process of job examination/analysis to consideration of what are the right and wrong questions to ask when attempting to elicit job-relevant responses from the candidate. The workshops teach delegates how to conduct reliable and valid structured behavioral-interviews in line with international best practice.
Hunter and Hunter (1984) in Huffcutt., AI (1994). Hunter and Hunter (1984) revisited: Interview validity for entry-level jobs. Journal of applied psychology, 79 (2), p. 184