The Natural Stories Corpus
Table 3: Regression coefficients and significance from individual mixed-effects regressions predicting RT for each of the three predictors log frequency, log trigram probability, and word length.
['Predictor', '^ [ITALIC] β', 'Std. Error', '[ITALIC] t value', '[ITALIC] p value']
In order to validate our RT data, we checked that basic psycholinguistic effects obtain in it. In particular, we examined whether the well-known effects of frequency, word length, and surprisal To do this, for each of the three predictors log frequency, log trigram probability, and word length, we fit a linear mixed effects regression model with subject and story as random intercepts (models with random slopes did not converge) predicting RT. Frequency and trigram probabilities were computed from Google Books N-grams, summing over years from 1990 to 2013. (These counts are also released with this dataset.) In keeping with well-known effects, increased frequency and probability both lead to faster reading times, and word length leads to slower reading times.