Ennis (1989) suggested that there a

Ennis (1989) suggested that there are a range of approaches through which critical thinking can be taught: general, where critical thinking is taught separate from content or ‘discipline’;infusion, where the subject matter is covered in great depth and teaching of critical thinking is explicit; immersion, where the subject matter is covered in great depth but critical thinking goals are implicit; and mixed, a combination of the general approach with either the infusion or immersion approach.Ennis (1990) arrived at a pragmatic view to concede that the best critical thinking occurs within one’s area of expertise, or domain specificity, but that critical thinking can still be effectively developed with or without discipline specific knowledge(McMillan, 1987; Ennis, 1990).