The evidence for the Terzuolo and Viviani central control model of timing in typing was questioned, using data collected from skilled typists and data published by Terzuolo and Viviani. (In this model keystroke times are generated in parallel from centrally stored, word-specific timing patterns. Differences in overall time to type a given word are attributed to multiplicative rate parameter, constant for a given typing of the word, but varying from one typing to another.) The three major lines of evidence cited in the model were researched: keystroke times expand or contract proportionally when words are typed slower or faster, the variances of keystroke times do not increase for successive letters in a word; and the times to type a given digraph exhibit work-specific differences. Investigation methods included two studies involving professional typists who transcribed normal prose and simulation of keystroke times. Analysis showed that keystroke times do not expand proportionally, the apparent constancy of variance is an artifact of the method that Terzuolo and Viviani used to transform the keystroke times, and effects of surrounding character context are sufficient to explain differences in digraph latencies and these effects cross work boundaries, showing they are not word-specific. (YLB)