Relationship of visual and name similarity of visually presented letters.

Pairs of letters were orthogonally varied with regard to the degree of their visual and name similarities. Each pair was repeatedly presented, alternating with a masking field, until the S gave an identification response. When similarity is high for one feature, the number of correct identifications increases as an inverse linear function of similarity of the other feature. When visual similarity is low, correct identifications increase as a direct linear function of name similarity. However, when name similarity is low, correctddentifications do not vary consistently with visual similarity. The results at high similarity of one feature are interpreted as a reflection of encoding processes, while the results at low similarity levels of the visual feature are interpreted as a reflection of decoding into response form.