This edition of The Research Digest is focuses on theory, research and policy issues related to the teaching of critical thinking. It examines different definitions and views of critical thinking, and different approaches to teaching critical thinking. In particular it examines ways of posing higher-order critical thinking questions and the teaching of routines for critical thinking. A key feature of this series of research digests is that each edition will focus on the Australian Professional Standards for Teachers (AITSL, 2012). This issue makes links to Professional Knowledge, Standard 1, Know students and how they learn, and Standard 2, Know the content and how to teach it. There are also clear links to Professional Practice, Standard 3, Plan for and implement effective teaching and learning, in relation to the focus areas of establishing challenging learning goals and using teaching strategies. The research digest draws on searches of a number of data bases and bibliographic resources, including the Australian education Index, education Resources Information Center (eRIC), education Research Complete, British education Index and Scopus. A selection of relevant websites is listed and a full reference list provided. Links to those references for which full-text online access is freely available are also included.