Hiring new employees can sometimes feel like a crap shoot. How a candidate interviews is frequently a poor indicator of job performance (except in fields like sales where presentation is key). Asking good questions in a structured way helps, as do portfolios and reference checks.
The best way to test candidates’ ability to do the job you are hiring for is to let them do it; at 70% predictive, producing a work sample is more reliable than any other method short of a trial period. If at all possible, give them a task that is representative of the job: Have a welder weld, a writer write, a salesman make a sale.
Set up the same test for each candidate so you have a valid basis for comparison. This not only helps with hiring, it provides evidence of proper hiring techniques in case of a discrimination-in-hiring charge.
Work samples frequently involve some make-work – welding a NC part, making a sale to the sales manager – but the expense is much cheaper than hiring the wrong person. If you have a candidate doing work that you will actually make use of, put them on the clock so they are properly paid for the work they do; make it very clear that this is a short-term arrangement for the purposes of evaluating their abilities and fit with the culture.
Work samples will often weed people out, since they know themselves better than you can so quickly. A good writer who is asked to write an article in 20 minutes may recognize that their test anxiety makes this task a poor fit for them and leave the process. As a result, you will be left with candidates who are less likely to quit after a few weeks.
For some jobs, it will take more than an hour or so to see if someone is a good fit. An option in this case is to hire them for a day or two and see how they fit in. This can be an annoying amount of paperwork for an interview process, but it is better than hiring the wrong person, doing all that paperwork, training them, and having them leave in a month or two. One possibility is to use a temp service to handle the paperwork.
Finding the right person to hire is never easy, but well-thought-out work samples can lead to a better result than a standard interview.