title: Speed-accuracy trade-off in skilled typewriting: decomposing the contributions of hierarchical control loops.
abstract: Typing performance involves hierarchically structured control systems: At the higher level, an outer loop generates a word or a series of words to be typed; at the lower level, an inner loop activates the keystrokes comprising the word in parallel and executes them in the correct order. The present experiments examined contributions of the outer- and inner-loop processes to the control of speed and accuracy in typewriting. Experiments 1 and 2 involved discontinuous typing of single words, and Experiments 3 and 4 involved continuous typing of paragraphs. Across experiments, typists were able to trade speed for accuracy but were unable to type at rates faster than 100 ms/keystroke, implying limits to the flexibility of the underlying processes. The analyses of the component latencies and errors indicated that the majority of the trade-offs were due to inner-loop processing. The contribution of outer-loop processing to the trade-offs was small, but it resulted in large costs in error rate. Implications for strategic control of automatic processes are discussed.
authors.affiliation: Department of Psychology, Vanderbilt University, Nashville,TN 37240, USA. motonori.yamaguchi@vanderbilt.edu
authors.forename: Motonori
authors.initials: M
authors.lastname: Yamaguchi
authors.forename: Matthew J C
authors.initials: MJ
authors.lastname: Crump
authors.forename: Gordon D
authors.initials: GD
authors.lastname: Logan
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology*; D006801:Humans; D009048:Motor Skills; D011597:Psychomotor Performance / Q000502:physiology*; D013647:Task Performance and Analysis; D013997:Time Factors; D014956:Writing