Text Reading Fluency and Error Patterns by Decoding Difficulty in Korean Second Graders with Developmental Dyslexia

Objectives: Reading fluency serves as a crucial component in learning to read Korean, a language with transparent orthography. Therefore, it is essential to examine reading fluency using decodable texts. This study aimed to compare text reading fluency abilities and errors between second-grade students with and without dyslexia, using texts with varying decoding difficulty.Methods: A total of 60 second-grade students participated, including 30 with dyslexia (DD) and 30 typically developing (TD). Participants read texts with two levels of decoding difficulty. Reading fluency was assessed based on the number of correctly read eojeol (i.e., Korean spacing units) per 10 seconds, eojeol accuracy, and reading speed. In addition, the number of errors across six types of reading fluency errors was analyzed. Results: The DD group showed significantly lower performance than the TD group in the number of correctly read eojeol per 10 seconds and reading speed. Eojeol accuracy did not differ significantly between groups for low-difficulty text, however, a significant group difference was observed for high-difficulty text. Error analysis revealed no significant group differences in the number of errors across all error types for low-difficulty text. In contrast, for high-difficulty text, DD showed significantly more errors in decoding, word substitution, within-phrase repetition, grammatical morpheme, and correction errors. Conclusion: Students with dyslexia showed comparable reading accuracy and improved reading speed when reading low-difficulty texts, highlighting the importance of using decodable texts. Grammatical morpheme errors were most frequent, highlighting the need for fluency instruction at the eojeol level, especially emphasizing grammatical elements, in reading interventions for students with dyslexia.