<![CDATA[This study evaluates students’ critical thinking in argumentative speaking at UPTD SMAN 1 Malunda, West Sulawesi. Critical thinking is an essential competence in English language learning because students are expected not only to express opinions but also to support their claims with logical reasons, relevant evidence, clear organization, and awareness of opposing views. This research employed a mixed-method design with a case study orientation. The participants were three Grade XII students selected through purposive sampling. Data were collected through an argumentative speaking test, in-depth interviews, and questionnaires. The speaking test required students to present oral arguments on a given issue through recorded video performance. The performances were transcribed and assessed using a critical thinking rubric consisting of five indicators: purpose/thesis, organization and clarity, argument, examples and facts, and opposing views. Interview data were analyzed through coding to explore the impact of critical thinking on learning independence, self-confidence, learning style, and physiological factors. Questionnaire data were used to identify students’ perceptions of argumentative speaking. The findings show that students demonstrated excellent critical thinking ability in argumentative speaking. Their scores were 90, 95, and 90, placing all participants in the excellent category. The students were able to state clear positions, organize ideas coherently, build logical arguments, provide examples, and recognize opposing views. Critical thinking also supported students’ learning independence, confidence, structured learning strategies, and reflective preparation. However, physiological factors such as lack of sleep, dizziness, fatigue, and nervousness affected concentration and speaking performance. The study concludes that argumentative speaking is an effective activity for evaluating and developing students’ critical thinking in English learning.]]>
