Why Assessment Centers May Not Be Effective in Recruitment

By all accounts, assessment centers should be the perfect recruitment tool. They tick all the boxes: they are highly structured, measure a wide range of competencies, and employ a variety of different tools to evaluate the quality of hire. Moreover, employing organizations place significant faith in assessment centers as a selection tool, as made evident by their high cost. But do assessment centers really deliver on their promises, and should organizations use them as their final stage selection tool?

In this article, I will outline the research in occupational psychology regarding assessment centers and their predictive validity, utility, and best practices in recruitment.

The Predictive Validity of Assessment Centers

Despite claims of being the most powerful and thorough selection tool available, the research is actually fairly scathing, showing only mediocre associations with job performance (Schmidt & Hunter, 1998). Indeed, assessment centers as a whole seem to be less predictive of performance than many of their individual constituent assessments, including interviews and psychometric tests. This may come as a surprise to many HR practitioners and hiring managers who use assessment centers regularly, but a large body of evidence confirms this finding.

More concerning, perhaps, is the overall cost-effectiveness of assessment centers as a talent assessment tool. Costs vary depending on the organization and structure of the assessment center, but many organizations spend well over a thousand dollars per applicant, making assessment centers one of the least cost-effective screening tools on the market. While there are many selection tools less predictive of performance, i.e., resume sifting, academic achievements, and reference checks, these are far more cost-effective than assessment centers, typically costing very little.

But why are assessment centers so ineffective relative to their cost? Is there anything we can do to improve their predictability?

The Problems with Assessment Centers

The first major problem assessment centers have is that, in many cases, they are simply redundant. If your organization has thoroughly screened beforehand, particularly using effective cognitive ability tests and personality questionnaires, all the subsequent applicants may be of comparable quality. Consequently, there may not be much to distinguish candidates from one another, reducing the effectiveness of the exercise.

Conversely, if the organization has done a poor job of screening beforehand, all the applicants could simply be average, the most likely outcome when screening people ineffectively. Once again, differentiating between average candidates is an exercise in futility, minimizing the utility of assessment centers. This is a particularly unfortunate outcome and would suggest that organizations are better served using that money earlier in the process instead of later.

Research also shows that assessment center scoring makes a big difference when it comes to predictability. Traditional wash-up style sessions, where assessors simply chat amongst themselves and make informal decisions, are significantly less effective than simply using a scoring tally (Dewberry, 2011). Naturally, wash-ups introduce the potential for bias, unreliability, and personal interest into the selection process, weakening its effectiveness. Instead, organizations should simply go by the scores on each exercise and hire the best-performing candidates available to them.

Lastly, not all assessment center exercises are created equal, and many are actually quite ineffective in and of themselves. For example, structured interviews are especially powerful predictors of performance in the workplace, but we have little to suggest that group exercises, presentation exercises, or case study exercises are useful tools for selection. Additionally, we have little evidence to provide guidance on how best to score these exercises, further confounding things. As a result, we may have a situation where too many chefs spoil the broth, and certain exercises reduce the average validity of the assessment process.

Conclusions and Recommendations

Although surprising to many, assessment centers simply do not live up to the hype. This makes sense when you think about it. If you have a thousand applicants at the beginning, your starting pool will contain more high-performers than in any other part of the process, and so it’s really the screening decision which influences candidate quality, not the 10 or 20 applicants at the end. If you haven’t done your legwork, and you haven’t ensured a high-quality shortlist, no amount of money, time, or effort will magically improve the quality of your applicants, and you cannot expect assessment centers to perform optimally.

Instead, organizations are well-advised to focus on the early stages of the recruitment process first, and once they are confident in their ability to effectively shortlist, then extend the budget to the final stage of the recruitment process, and not the other way around.