A job interview typically precedes the hiring decision, and is used to evaluate the candidate. The interview is usually preceded by the evaluation of submitted résumés from interested candidates, then selecting a small number of candidates for interviews. Potential job interview opportunities also include networking events and career fairs. The job interview is considered one of the most useful tools for evaluating potential employees. It also demands significant resources from the employer, yet has been demonstrated to be notoriously unreliable in identifying the optimal person for the job.[5] An interview also allows the candidate to assess the corporate culture and demands of the job. Multiple rounds of job interviews may be used where there are many candidates or the job is particularly challenging or desirable. Earlier rounds may involve fewer staff from the employers and will typically be much shorter and less in-depth. A common initial interview form is the phone interview, a job interview conducted over the telephone. This is especially common when the candidates do not live near the employer and has the advantage of keeping costs low for both sides.