This study aims to find out: (1) the process of preparing teaching materials based on critical thinking in learning to write explanatory text; (2) the feasibility of teaching materials based on critical thinking in learning to write explanatory text; and (3) the effectiveness of teaching materials based on critical thinking in learning to write explanatory text. This type of research was research and development (R & D) based on Borg and Gall development model adapted from Sanjaya. Data collection techniques carried out included observations, interviews, questionnaires, and tests regarding explanatory text material. The subjects of the trial consisted of individual trials (3 students), small group trials (9 students) and large-scale trials (30 students). The results of the study showed that: (1) material expert validation as a whole reached an average of 85.20% on very good criteria; (2) the validation of learning design experts as a whole reached an average of 84.58% on very good criteria; (3) teacher response with an average of 89.84% on very good criteria; (4) students’ responses to individual trials with an average of 85.48% on very good criteria, small group trials with an average of 90.42% on very good criteria and large scale trials with an average of 93.76 % on very good criteria; (5) the effectiveness of teaching materials is shown from the learning outcomes of the written test, the explanation of the students before using the module was 66.5%, while the learning outcomes of the students’ expedition text writing test after using the module increased by 82.17%. The difference obtained was 15.67% from before to after. The results showed that teaching materials based on critical thinking in explanatory text writing learning are feasible and effective to be used as learning resources.
Keywords: Critical thinking, Development, Explanatory Texts, Teaching Materials
