Construction and validation of a Thurstone scale of liberalism—conservatism.

A 23-item scale of liberalism—conservatism was constructed by the Thurstone method of equal-appearing intervals and found to correlate highly (point-biserial r = .64) with a naturalistic behavioral criterion consisting of self-selected, actively campaigning political groups (Young Democrats and Young Republicans). The scale yielded an internal-consistency coefficient of .79, indicating substantial common variance among items, and a coefficient of reproducibility of .87, indicating quasiscalability. A considerably greater proportion of non-perfect scale types, as evidenced by a significantly greater number of errors of reproducibility (p