There is no golden rule about the appropriate number of interviewers for an interview. It is important, however, to involve the prospective candidate's direct boss at some point. However objective the interview may be, the chemistry between the new hire and his or her boss must be right. Yet the most common interviewing mistake, says Baron, is to rely on 'chemistry' and gut feeling in preference to a well-planned, structured interview. Most untrained interviewers favour unstructured interviews in which they pose their favourite questions, based on the application form, work history, aspirations, personal circumstances etc.
Research proves that structured interviews are significantly more effective than unstructured ones.
The advantage of structured interviews, whether situational or behavioral, is that they are a far more effective predictor of performance than the unstructured interview. Moreover, structured interviews are generally better perceived by candidates, who feel that the interview has been more relevant and thorough. Prior to the interview, the employer should draw up an accurate job description and person specification, which outline the personal attributes, experience, skills and competencies required for the job. It is worth remembering, however, that not all competencies can be explored by interview alone. But, says Baron, any company can increase the predictive power of the interview by including a short, practical work test.