Calculation of signal detection theory measures


Signal detection theory (SDT) may be applied to any area of psychology in which two different types of stimuli must be discriminated. We describe several of these areas and the advantages that can be realized through the application of SDT. Three of the most popular tasks used to study discriminability are then discussed, together with the measures that SDT prescribes for quantifying performance in these tasks. Mathematical formulae for the measures are presented, as are methods for calculating the measures with lookup tables, computer software specifically developed for SDT applications, and general purpose computer software (including spreadsheets and statistical analysis software).

We are indebted to James Thomas, Neil Macmillan, John Swets, Douglas Creelman, Scott Maxwell, Mark Frank, Helena Kadlec, and an anonymous reviewer for providing insightful comments on earlier versions of this manuscript. We also thank Mack Goldsmith for testing some of our spreadsheet commands.