Process of recognizing tachistoscopically presented words.

A model for the recognition of tachistoscopically presented words is developed. The model is a "sophisticated guessing" model which takes explicit account of the geometry of the characters which make up the words or letter strings. Explicit attempts are made to account for word frequency effects, effects due to letter transition probabilities, and effects due to physical similarity of character strings to one another. A word recognition experiment using the set of three-letter words is reported, and the model is used to make quantitative predictions of these results as well as to give a qualitative account for a number of results in the literature. Finally, it is shown that under certain simplifying assumptions this sophisticated guessing model is isomorphic with the "criterion bias" model as developed in 1967 by Broadbent. The process whereby words are recognized has long fascinated experimental psy-Several related findings have commanded the most attention. For example, more letters per unit time may be apprehended when a word is presented than when a string of unrelated letters is presented (Huey, 1908). A letter string formed by taking a word and either deleting or replacing one or two letters is often clearly perceived as that word (Pillsbury, 1897). Other things being equal, words which occur frequently in the language are more easily perceived than those which occur less frequently (Goldia-The more the statistics of letter strings approximate those of words, the better the perception of the letter strings (cf. Miller, Bruner, & Postman , 1954). The more predictable a word is within a sentence, the more easily it is Most explanations of these phenomena suggest that they all result from the fact that the subject combines internally provided information about language with externally provided information from the sensory system (cf. Morton, 1969, 1970). By this argument, words are easier to see than nonwords because we can apply our knowledge of the vocabulary of the language. Knowledge of relative frequencies of words in the language allows us to read high-frequency words more readily. Knowledge of syntactic and semantic relations allows us to read words more easily in the context of 99