Does the consistency of mapping between spelling and sound of L2 words affect vocabulary knowledge?

Abstract This study examined the impact of sound-and-spelling consistency of L2 English words on written vocabulary knowledge among Japanese learners studying English as a foreign language (EFL). In Study 1, 162 Japanese participants completed a multiple-choice meaning recognition test based on the updated Vocabulary Levels Test VLT; in Study 2, 107 Japanese participants completed a spelling test, adapted from the VLT used in Study 1. Two directions of consistency at the rime level (i.e., phonology to orthography and orthography to phonology) were analyzed, while controlling for other word-related variables (e.g., word frequency and cognateness). Although exploratory analyses revealed that the consistency effect emerged under controlled conditions for specific word types (i.e., noncognates) and frequency bands (i.e., high-frequency vocabulary), no reliable consistency effect was observed irrespective of test formats. These findings suggest that consistent words are not necessarily easier to learn, particularly for EFL learners whose L1 writing system is not alphabetic.