Confusion matrix analysis for form perception.

The Constant-Ratio Rule (CRR), an empirical technique for analysis of confusion matrices, was developed for use in predicting intelligibility of speech syllables. This study investigated the validity of the rule when applied to the data from experiments on visual form perception. English letters and simple geometric figures were tachistoscopically presented in the center of a viewing field. Response proportions for subsets of this master set of stimuli were predicted by CRR. Results indicated that the rule (/) accurately predicted numeric response proportions for subsets of stimuli when experimental conditions were similar and (2) predicted ordinally accurate data when experimental conditions varied within the limit which might be encountered in "operational situations." These results, as well as arithmetic factors which can result in errors in prediction, are discussed.