Critical Thinking skill is the ability of cognitive process in developing logical and reflective judgement about what someone believes and does and the ability to analyze and evaluate thought.Critical thinking skill will help the students to decide what sources of information that will be used to support their idea, how to interpret those infomation and organize their writing to be more logical and accurate. The Discussion section in the thesis presents and discusses the findings in details and it needs the reseacher strong argument to convince the reader about the findings. The purpose of the research is to find out and explain the six core of critical thinking skills reflected in discussion section of the thesis written by the graduate english students of Universitas Negeri Padang. The source of data in this research was 9 documents of discussion section of the thesis written by graduate English students of Universitas Negeri Padang. Descriptive using qualitative approach was used in this research. The result of this research reveal that there were 244 times critical thinking skill reflected in the 9 documents of discussion section of the theses written by graduate english students of Universitas Negeri Padang. The finding shows that the students applied four skills out of six critical thinking skills in writing discussion section of the thesis. They were explanation skill 97 times (39.75%), analysis skill 95 times (38.93%), interpretation skill 43 times (17.62%), and inference skill 9 times (3.68%). The evaluation skill and self-regulation skill did not found in this research. Those skills are important skills in writing discussion section of thesis which basically contain depth exploration of the result of the research, interpreting it, and comparing it with existing and relevant theory.

Bavdekar, Sandeep B. 2015. Writing the Discussion Section: Describing the Significance of the Study Findings. The Journal of the Association of Physicians of India.Vol.2.

Emilia, Emi. 2010. Analyzing Students’ Critical Thinking in Writing a Thesis Using the Transitivity System. Jurnal Ilmu Pendidikan,Jilid 17, Nomor 2.

Facione, Peter A. and Facione, Noreen C. 1994. The Holistic Critical Thinking Rubric. The California Academic Press.

Facione, Peter A. and Gittens, Carol Ann. 2013. Think Critically. United Kingdom: Pearson Education, Inc.

Guleker, Rudina. 2015. Instructional Strategies to Foster Critical Thinking: Self-Reported Practices of the Faculty in Albania. International Journal of Teaching and Education Vol. 3 No. 4.

Indah, Rohmani N. 2017. Critical Thinking, Writing Performance and Topic Familiarity of Indonesian EFL Learners. Journal of Language Teaching and Research, Vol.8, No.2.

Pei, et all. 2017. Critical Thinking and Argumentative Writing: Inspecting the Association among EFL Learners in China.English Language Teaching. Canadian Center of Science and Education. Vol. 10, No. 10.

Pramonojati, et all. 2020. Students’ Critical Thinking in Writing Background of Research. International Conference of English Language Testing, Vol.434. Atlantis Press.

Putri, Riza Oktari. 2018. Investigating the Link between Critical Thinking Skill and Argumentative Writing Skill: The Case of Islamic Senior High School. Jurnal Pendidikan dan Pengajaran, Vol.5, No. 2.

Qasseem, Mutahar. 2017. Thesis, Dissertation and Article Writing. Research Gate, (https://www.researchagte,net/publication/318661780, diakses 14 Januari 2019).

Rachmawati, Yuli. 2015. An Analysis of Critical Thinking Aspects in Students’ Discussion Texts. Unpublished Thesis of UniversitasPendidikan Indonesia.

Sharaqah, Dr. Talha Abdullah. 2014. Developing Critical Thinking Skills through Writing in an Internet-Based Environment. International Journal of Humanities and Social Science,Volume 4 No. 1 Januari 2014.

Tim penyusun .2011. Buku Panduan Penulisan Tesis dan Disertasi Program Pascasarjana. Padang: Universitas Negeri Padang