OICC Press Journal of New Trends in English Language Learning (JNTELL) 2821-2290 3 5 2024 07 28 Exploring the Effectiveness of Artificial Intelligence (AI) on Reading Comprehension among Iranian EFL Learners 10.71528/2024.202406221123351 EN Mahdi Yousefi Department of English Language, Central Tehran Branch, Islamic Azad University, Tehran, Iran Mohammad Iman Askari Department of English Language, Central Tehran Branch, Islamic Azad University, Tehran, Iran Journal Article 2024 07 28 This study aimed to investigate the impact of AI, specifically Chat GPT, on the reading comprehension abilities of Iranian English as a Foreign Language (EFL) learners. Participants (N=54) were selected through a convenience sampling method from two universities in Tehran, Iran. Eligible participants underwent an NPT language proficiency test to ensure homogeneity within the sample. Random assignment was conducted to allocate participants into either the experimental group (exposed to Chat GPT) or the control group (without exposure to Chat GPT). Pretests and posttests were administered to measure the participants' reading comprehension abilities before and after a ten-week intervention period. Data analysis, including independent-samples t-tests and Cohen's d calculations, revealed a significant difference in reading comprehension gain between the experimental and control groups. The experimental group demonstrated a substantial increase in reading comprehension skills, while the control group showed a slight decrease. The effect size, as measured by Cohen's d, was found to be very large (5.33), indicating a significant impact of Chat GPT on EFL learners' reading comprehension abilities. These findings support the conclusion that the use of AI, particularly Chat GPT, positively influenced the reading comprehension levels of EFL learners.