Shiraz University Teaching English as a Second Language Quarterly 2981-1546 44 3 2025 06 01 Unmasking Inconsistency in Relative Clause Ambiguity Research: A Systematic Methodological Review 55 107 7984 10.22099/tesl.2025.51984.3367 EN Karim Vafaee Seresht University of Tehran, Tehran, Iran Hamideh Marefat University of Tehran, Tehran, Iran Abbas Ali Rezaee University of Tehran, Tehran, Iran Journal Article 2024 12 21 <strong>Research on relative clause (RC) ambiguity resolution in first and second-language contexts has produced conflicting results, with some studies indicating a preference for high attachment, others favoring low attachment, and some reporting no clear preference. In conjunction with other variables, these mixed results may be due to variations in the methodological features employed across studies. Therefore, there is a pressing need for a systematic review of the methodological features of relevant offline tasks to evaluate how these differences may lead to conflicting results critically. To address this issue, a systematic methodological review was conducted analyzing 108 features of offline tasks, including identification, context, materials, design, administration, data analysis, open science practices, and transparency. The results revealed significant methodological variation in the literature and a moderate mean transparency score of 59.77. These findings emphasize the need for methodological standardization and greater transparency in future research to ensure reliable and comparable RC ambiguity resolution research results. </strong> https://tesl.shirazu.ac.ir/article_7984_ea1ef0e7256b6b48978b087f19836940.pdf