Few concepts in higher education are of greater interest and importance than the notion of critical thinking. Writing can be a mechanism for both demonstrating that critical thinking has occurred and as a mechanism for catalyzing it to occur. Writing can demonstrate critical thinking in papers and other written texts which can be thought of as critical thinking product/performance (finished formal papers, projects). Writing can also cause critical thinking to occur as students engage with material through the generation of texts in response to material they are learning. In this case, critical thinking is more process, a form of engaged inquiry or directed learning that is elicited by writing.
In all cases, a central element of critical thinking is a dialogic approach. So with a critical thinking writing prompt, a student is not asked to recite information from text or lecture, but to explain and evaluate multiple perspectives from a variety of sources he or she has come in contact with. The strategy is about working from a question or problem and struggling to evaluate and make sense of it from available information and data.