Wesman, A. G. (1949). Effect of Speed On Item-Test Correlation Coefficients. Educational and Psychological Measurement, 9(1), 51–57. http://doi.org/10.1177/001316444900900106

[Concerning time-limits in academic testing …]

“In the construction of objective tests, one sometimes deliberately injects a factor of speed because of the conviction that speed is an important component of the ability to be measured. More frequently, this is _not_ the reason. In most group tests, especially those designed for selection purposes, the speed factor represents a compromise for the sake of administrative efficiency.” (p 51)