Does radical type frequency reliably affect character recognition? Zih-Nian, Cong & Jei-Tun, Wu

1. Does radical type frequency reliably affect character recognition? Zih-Nian, Cong & Jei-Tun, Wu Department of Psychology, National Taiwan University, Taipei, Taiwan Introduction ■ Type frequency and token frequency treated as radical frequency are considered as a potential factor to affect the performance of character recognition. However, the computation of radical type frequency is confounded with the concept of neighborhood. ■ A number of previous studies (e.g., Taft and Zhu, 1997; Wang, 2002) about type frequency and token frequency have been compared but it has not yet reached a consistent conclusion. ■ In this study, Naming Task (NT) was used to examine the role of radical type frequency played in character recognition. Methods Participants Nineteen in EXP1 and thirty-five in EXP2 NTU students. Design & materials ■ The design was a 2 (character frequency) x 2 (type frequency of the left radical) x 2 (type frequency of the right radical) design in both experiments with all three factors being within-subjects. ■ The purpose of EXP1 was to replicate the experiment1 of Wei (2002). The materials used in EXP1 were the same as those in Wei(2002). ■ In EXP2, each set of 15 left-right characters were selected as stimuli using the same principle in Wei(2002). In addition, 60 left-right characters in medium character frequency were used as filler characters. Procedure Each subject received all of the items, which were presented in random order on a computer screen. Naming task(exp1 and exp2) was used. The reaction time and error rate were recorded as dependent variables. Discussion ■ The results of the two experiments demonstrated the inhibited effect of the type frequency of the left radical. That is to say the more a left radical appears in different characters, the more time it is required to be correctly identified. ■ However, the present studies showed an unstable inhibition effect of the type frequency in left radicals because the slight difference in the materials may lead to the effect demonstrated in different conditions. ■ In comparison with character frequency, the effect of radical type frequency has unstable pattern of effects across different studies and different tasks. ■ Therefore, the exact role of type frequency is still uncertain, and it requires more elaborate studies in the future. Results ■ Character frequency was the most effective factor. ■ In EXP1, the main effect of the type frequency of the left radicals and its interaction with character frequency were both significant, with the simple main effect demonstrating an inhibited effect of left radicals when the character frequency was high. In addition, the interaction between the type frequency of the left and the right radicals was also significant, and it indicated an inhibited effect of right radicals while the left radical was in low frequency. ■ In EXP2, as in EXP1, the overall effect of the type frequency of the left radicals showed up as being significant, while its interaction with the character frequency was also significant. Acknowledgement This study is partly supported by National Science Council, Taiwan.(NSC 94-2413-H-002-030) Correspondence : jtwu@ntu.edu.tw