This is clearly not only an interesting but also an important area of research. However, as selection methods change so research has to catch up. A great deal of selection is now web-based, which brings its own set of challenges and opportunities for both professional and researchers. It is now possible to gather a great deal of information about candidates via social media which, though interesting, may conflict with what they report to potential employers. In this sense unobtrusive methods can be used to evaluate people.
There are also important developments in the biological and neurosciences which suggest that using physiological methods for selecting in, and out, may prove very important. However, both developments pose ethical issues, which practitioners and researchers will have to face.
This chapter has looked at three types of data that recruiters and selectors often have access to, to help them make better decisions. Without doubt most of the work in this area has concerned biodata, that is the analysis of how the biography of an individual can be used to predict their behaviour at work. There is much less work on references and CVs because it is recognized that there is considerable bias in these documents. This area is often difficult to research and is not usually theoretically driven. Nevertheless, the very frequency with which application forms, resumes and letters of reference are used in assessment and selection suggests it is an area which merits more and better research.