Yesterday, Stefan Valdimarsson wrote to tell me about an interesting error in one of my recent posts. It was a typing error, but not one of the common slips of the finger that have been catalogued, counted and modeled over the decades, from D.D. Lessenberry's 1928 "Analysis of Errors" (published by Corona Typewriters, and reprinted in Dvorak et al., Typewriting Behavior, 1936) to the "Glossary of Terms Including a Classification of Typing Errors" by D. Gentner et al., in W.E. Cooper's Cognitive Apects of Skilled Typewriting, 1983.
This wasn't a keystroke substitution error, nor a transposition of two sequentially adjacent keystrokes, nor an interchange of keystrokes that are not serially adjacent, nor a migration of keystrokes to a position earlier or later than the canonical order, nor a keystroke omission, nor a keystroke insertion, nor an abstract doubling error (like "aad" for "add") or alternation error (like "threr" for "there"). Such errors are a fascinating subject, as you can learn by reading David Rumelhart and Donald Norman's seminal paper "Simulating a skilled typist: A study of skilled cognitive-motor performance", Cognitive Science 6(1) 1-36, 1982.
But this wasn't really a keystroke error at all.
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