• Critical thinking, in its broadest sense has been described as "purposeful reflective judgment concerning what to believe or what to do." 

Principles and dispositions

• Critical thinking is based on self-corrective concepts and principles, not on hard and fast, or step-by-step, procedures.

Applications

Critical thinking is about being both willing and able to evaluate one's thinking. Thinking might be criticized because one does not have all the relevant information—indeed, important information may remain undiscovered, or the information may not even be knowable—or because one makes unjustified inferences, uses inappropriate concepts, or fails to notice important implications. 

Research in efficiency of critical thinking instruction

• Research suggests a widespread skepticism about universities' effectiveness in fostering critical thinking. For example, in a three year study of 68 public and private colleges in California, though the overwhelming majority (89%) claimed critical thinking to be a primary objective of their instruction, only a small minority (19%) could give a clear explanation of what critical thinking is. 

Cultivation

• There is no simple way to develop the intellectual traits of a critical thinker. One important way requires developing one's intellectual empathy and intellectual humility.