PDD test in which a single issue is addressed and is always given after a multiple-issue test has indicated that the examinee has consistently responded to that issue. It is generally conducted in one of the validated test formats, such as Zone Comparison Tests or the Modified General Question Test. Question coverage can be single- or multi-faceted. The rationale for this two-stage approach to PDD testing is that, while multiple-issue screening examinations are very useful in identifying which among several issues the examinee is concerned with, they lack the power of these single-issue formats in making correct determinations of deception or truthfulness. This approach is used in many polygraph screening programs to maximize both the utility and accuracy of PDD in pre-employment screening and other applications.
