Introduction

Global education requires critical thinking. In an age in which information is selected and presented in increasingly sophisticated ways, when the only constant feature is change and when problems must be solved quickly, thinking is a survival skill for the individual and the society alike. The world summit on teaching (Asia Society, 2012) claims that only providing higher order skills for the majority of students is an adequate goal and, in addition, future world citizens not only need subject knowledge, but also a wide range of skills and attitudes. However, how these higher order skills are defined, and the balance among various abilities, knowledge and values, varies from country to country. The Assessment and Teaching of 21st Century Skills consortium, which includes countries from across the globe, provides one widespread definition. This definition divides 21st century skills, knowledge and attitudes into four categories. Among these categories, ways of thinking comprising elements of creativity/innovation, critical thinking, problem-solving, decision-making and learning to learn completed with a positive attitude to learning are considered to be key factors.

Regarding its social aspects, critical thinking is also a key competence in performing citizenship activities, which is also a reason why researchers and educators worldwide have recently focused on identifying and developing the strategies, competencies and attributes of critical thinkers.

Despite the widespread effort, we still face a lack of consensus regarding the definition of critical thinking. The purposes of this paper are to: (a) explore the ways in which critical thinking has been defined by researchers; (b) investigate how critical thinking definitions can be extended into a more comprehensive framework for the analysis of theory and practice in the classroom; (c) learn what role language may have in the research of classroom critical thinking; and (d) draw conclusions and further implications for future development and research in the subject.