Identifying, acquiring, and developing valid and reliable instruments are major problems facing researchers who study psychosocial drug use and abuse. Much time is often devoted to creating a measuring device when an adequate one already exists, resulting in duplication of effort, considerable waste of resources, and loss of uniform comparability…

Most methods of personality scale construction have clear statistical disadvantages. A hybrid method (Darlington and Bishop, 1966) was found to increase scale validity more than any other method, with large item pools. A simple modification of the Darlington-Bishop method (algebraically and conceptually similar to ridge regression, but…