Abstract
Critical thinking has been widely considered an important skill in the 21st century. In view of the value attached to critical thinking, various quantitative instruments have been developed to assess critical thinking, which only provide a product of critical thinking and cannot reveal the critical thinking process of test takers. Hence, this paper proposes a coding scheme facilitating a qualitative analysis of critical thinking exhibited in interaction. The coding scheme consists of five categories of critical thinking skills, i.e., analysis, comparison, evaluation, inference, and synthesis, each of which is coded at low, medium, and high levels. The use of this coding scheme is then illustrated by applying it to authentic classroom dialogue. This coding scheme is hopefully conducive to the assessment of critical thinking in educational settings.