This study empirically investigates the causal relationships among learners’ perceptions of QuillBot effectiveness, learner autonomy, and writing anxiety in an EFL context. QuillBot, an AI-assisted writing tool providing paraphrasing and grammar-checking functions, was selected as the primary tool for student revision. Fifty-six undergraduate students majoring in Aviation Maintenance participated. Three instruments were employed to measure the constructs: learners’ perceived effectiveness of QuillBot, L2 writing autonomy, and L2 writing anxiety. Data were analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). Results indicate that students’ perceptions of QuillBot effectiveness positively influence writing autonomy, which in turn significantly reduces writing anxiety, while perceived effectiveness did not have a significant direct effect on writing anxiety. The findings suggest that perceiving QuillBot as an effective tool enhances learners’ control over their writing, highlighting the mediating role of learner autonomy in AI-assisted L2 writing. The results provide practical implications for integrating AI-assisted writing tools into L2 instruction to foster learner autonomy and reduce writing anxiety.

1. INTRODUCTION
2. LITERATURE RIVEW
    2.1. Effectiveness of QuillBot
    2.2. Learner Autonomy in L2 Writing
    2.3. L2 Writing Anxiety
3. METHODOLOGY
    3.1. Participants
    3.2. Instruments
    3.3. Data Collection and Analysis
4. RESULTS
    4.1. Reliability and Validity of Measurement Model
    4.2. Structural Model Analysis and Hypothesis Testing
5. DISCUSSION
6. CONCLUSION
REFERENCES

• Hyewon Cho(Associate Professor, Department of Liberal Arts, Far East University, 76-32 Daehak-gil, Gamgok-myeon, Eumseong-gun, Chungcheongbuk-do 27601, Korea)