Word frequency during copytyping.

Two experiments examined effects of visual encoding and of manual motor programming during copytyping. In Experiment 1, expert typists copied sentences containing high- or low-frequency target words; instructions emphasized either the speed of typing or text comprehension. The results showed increased typing times for words preceding low frequency targets in the comprehension condition. However, pretarget typing was not affected by target frequency when speed of typing was emphasized, indicating that the visual encoding of text does not affect concurrent keypresses. Low-frequency words themselves were typed slower than high-frequency words. Supplementary analyses indicated that word frequency may affect the programming of a sequence of keystrokes forming a word. Consistent with this assessment, Experiment 2 showed that effects of word frequency cannot be reduced to movement practice.