Myers, C. T. (1952). The factorial composition and validity of differently speeded tests . Psychometrika , 17 (3), 347–354. https://doi.org/10.1007/BF02288766

Three forms were administered in different groupings of items to determine if practice on the test affected speed of completion.

Six hundred midshipmen at the U.S. Naval Academy participated.

On a figure classification test, nineteen scores were summarized on attempted and correct items.

The most valid test is one which is moderately speeded and can be completed by 70% of the candidates. On the speeded test, ability and rate of answering form two orthogonal factors.