Timeline of EverythingDisc
1950s - Early measurement of DiSC concepts: Self-Description instrument
A staff member of Walter Clarke Associates developed an assessment for John Cleaver, which they called Self Discription. It began like the Activity Vector Analysis as an adjective checklist, but evolved into a 24 tetrad, forced-choice instrument. Presumably, the forced choice aspect of the instrument was introduced to minimize the influence of socially desirable responding. Factor analyses of the Self Discription produced two factors that closely approximated the underlying axes of Marston’s model, lending considerable empirical support not only to the structure of the model he proposed, but to Clarke’s earlier claim that a DiSC®-based instrument could be created.