The challenge is to decide between purely objective criteria (who is the most qualified person for the job) and subjective (who will be the best fit for my company).
Not all assessments are suitable for use as pre-employment assessments. Psychological assessments that were designed for clinical or diagnostic use, for example, should not be used. The courts have consistently ruled that psychological testing generally has no place in the business environment.
An assessment – properly administered – is invaluable to the hiring process and can increase your productivity while reducing your turnover. I personally favor and administer the Kolbe Assessment program. But find out what works best for you – make sure to involve an expert in the process.