How Valid are Assessment Methods?

August 5th, 2011 by Sarah Green Leave a reply »

Within Zircon, Dr Amanda Potter and our other Business Psychologists recognise that making sure something is valid is fundamental to an assessment or development programme. Validity is measured by correlating the results from the assessment with the future performance. This is called predictive validity. The table above shows the predictive validity of various assessment and development tools.

From this table we can see that the Assessment Centre (or Development Centre) is the most valid (r = 0.65), in other words, it most accurately predicts future performance (or potential). The next valid assessment method is a single work sample exercise (such as a case study, presentation, role play for assessment, group exercise for development) (r = 0.5).

The ability tests (r = 0.45) are also high in terms of validity and they are closely followed by competency interviews (r = 0.35) and personality questionnaires (r = 0.32).

In isolation, none of these assessment methods are particularly strong, however in combination, their strength improves.

So what does this mean?

In order to understand the percentage of future behaviour that we can therefore account for using these assessment methods, we need to square the level of correlation (r). The graph below demonstrates this for each assessment method. We can therefore see on the graph overleaf that the assessment centre (multiple activity) method is the most valid and can predict over 40% of future performance or potential.

If you would like to assess the validity of your assessment or development centre, or want to check that it is measuring potential rather than performance, please contact Dr Amanda Potter on 01737 555 862.

Written by Dr Amanda Potter and Melissa Tyson – both Occupational Psychologists

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