Abstract
The present study investigates how second language (L2) speaking performance is improved by two factors that may affect cognitive and psychological burden: planning and topic type. Thirty-one Japanese university students completed four speaking tasks, mostly via an online platform. Their speaking performance was investigated based on the Bilingual Speech Production Model (Kormos, 2006). In the 2 × 2 full-factorial design, the two within-participant independent variables were one-minute planning (planned or unplanned) and topic type (argumentative or expository). The four dependent variables were fluency, complexity, accuracy, and lexical diversity measures. This design aims to bridge the L2 acquisition field and English instruction at Japanese schools based on the domains of planned production and unplanned interaction with topic categories concerning daily and social issues. Multivariate analyses reveal that planning significantly increases the number of spoken words, suggesting that planning could facilitate L2 lexical encoding. Additionally, interaction effects between planning and topic types demonstrate that accuracy is enhanced significantly when personal issues are described in expository topics under the planned condition. This result indicates that facilitated lexical encoding might assist participants in paying more attention to grammatical and lexical accuracy. These positive effects hold pedagogical implications for the improvement of L2 speaking performance.
