Whilst it can be tempting to see the process of interviewing as one process. It is useful to identify the three distinct stages of the PRI: gathering evidence, assessing competence, and, making recommendations.
During the interview, the main focus should be upon gathering evidence. One of the largest barriers to this is if an assessor makes too rapid a conclusion about an individual’s abilities. In such a case, the danger is that the interviewer will tend to focus on evidence which confirms his or her own preconceptions and underestimate the significance of evidence which contradicts them. Whilst there is no direct research into this aspect of interviewing in relation to professional assessment interviewing, there is much research into the efficacy and behaviour of interviewers when selecting for jobs.
By correlating the decisions that would be made after various amounts of time in an interview, it has become clear that the majority of untrained interviewers have effectively made their decision about candidates within thirty seconds of the start of the interview. This is in the context of interviews which, on average, last between twenty five minutes and an hour and a half, depending on levels of seniority.
This would be less worrying if there was a high correlation between the quality of the decisions made at interview and employees’ subsequent performance. Unfortunately again the performance of untrained interviewers in accurately predicting subsequent performance is extremely poor.
Research where people have compared predictions made at interview with performance after six or twelve months in the job often shows extremely poor predictive efficiency, often apparently worse than tossing a coin!