First-order approximation to English, second-order approximation to English, and orthographic neighbor ratio norms for 925 nouns

First- and second-order approximations to English and orthographic neighbor ratio values are provided for Paivio, Yuille, and Madigan's (1968) 925 nouns. First- and second-order approximations to English are information theory measures of the probability of generating a word on a letter-by-letter basis. The orthographic neighbor ratio is the frequency of a word divided by the sum of the frequencies of all words that can be generated by changing one of its letters. Thus, the orthographic neighbor ratio provides a measure of a sophisticated guessing model in which partial information about a word is obtained and a decision is made on the basis of the relative frequencies of the possible responses. Correlations with existing norms are reported. © 1981 Psychonomic Society, Inc.