One of the most challenging and yet rewarding experiences in teaching any college course occurs when the professor is faced with dispelling a popular myth or misconception that students hold in their belief system. It is challenging because beliefs are part of an entire system of understanding, and the process of changing a belief typically requires considerable effort by both professor and students. Ideally, beliefs are based on solid reasoning and good data, so changing a belief may mean changing the way someone reasons and the data that are accepted as valid. In changing a belief, educators need to understand how students explain events. For example, if someone is thinking about a friend and the friend calls him moments later, is this evidence of chance or a premonition? It is not easy to get most people to consider all of the people they think about everyday and realize that, just by chance, sometimes they will get a phone call from the very person who occupied their thoughts in the last few minutes.

The reward for the professor occurs when students can understand faulty reasoning patterns and distinguish good data from poor data. The deconstruction and rebuilding of a belief system requires critical thinking. The term critical thinking refers to the use of those cognitive skills or strategies that increase the probability of a desirable outcome. It is purposeful, reasoned, and goal directed. It is the kind of thinking involved in solving problems, formulating inferences, calculating likelihoods, and making decisions. When people think critically, they are evaluating the outcomes of their thought processes—how good a decision is or how well a problem is solved. Critical thinking also involves evaluating the thinking process—the reasoning that went into the conclusion arrived at or the kinds of factors considered in making a decision.

Professors who teach introductory courses (e.g., introduction to psychology, critical thinking, and life span and human development) are often faced with common misconceptions. Examples of misconceptions include the credibility and use of astrological readings, belief in the power of healing crystals, and reliance on shoddy research to justify a belief in products such as the use of shark oil to cure cancer or copper bracelets to relieve the pain of arthritis. Students must engage with new information in a conscious and critical manner for these misconceptions to be replaced with a new belief system.


Critical thinking is one type of thinking. Other types are the use of random methods to arrive at a conclusion, rote memorization, day and night dreaming, and sloppy thinking. Critical thinking is not a new idea. The philosopher John Dewey, who wrote about this topic at the turn of the 20th century, advocated for teaching skepticism, reflective inquiry, and tolerance for ambiguity, while working to reduce uncertainty. Students must be taught to consider evidence, from multiple sources, in order to solve problems. What is now thought of as critical thinking had a place in Dewey's basic writings. For Dewey, schools act as a repair organ for society, and it is through education that students can learn to think critically so that society can work toward self-improvement.

Diane Halpern (2003) notes that different types of information can be held or processed by different cognitive processes. For example, information in the form of speech is processed differently than visual information. In fact, these are examples of the two preferred modes of thought; silent speech and imagery. Based on these two types of processing information, different cognitive strategies are used during the critical thinking process.

The notion of different cognitive processes dealing with different information is related to the definition of critical thinking. Halpern defines the term as follows:

Critical thinking is the use of those cognitive skills or strategies that increase the probability of a desirable outcome. It is used to describe thinking that is purposeful, reasoned, and goal directed—the kind of thinking involved in solving problems, formulating inferences, calculating likelihoods, and making decisions, when the thinker is using skills that are thoughtful and effective for the particular context and type of thinking task (2003, p. 6).

The student who believes in astrological readings may focus on those outcomes that confirm the predictions made in the readings, which are always vague enough that almost anyone can find confirmation for the predictions. Another key element to critical thinking is an awareness of one's own thinking. Metacognition, or knowledge about what a person knows and how the person thinks is a key concept in the critical thinking literature because students need to have an awareness of the process and outcome of their thinking in order to consciously improve how they think.


Critical thinking is a developmental process that can begin at an early age. When thinking about critical thinking, people need to keep their definitions developmentally appropriate so that what constitutes critical thinking in the elementary school grades will differ from what is expected of an adult. William Perry conducted a survey of the thinking processes of students at Harvard University and Radcliffe College in 1953. Perry later (1968) devised an intellectual development model based on his analysis of survey responses. Although Perry's model was not designed to describe the development of critical thinking, it does describe many of the characteristics of a critical thinker such as open-mindedness, flexibility, willingness to self-correct, and pursuit of consensus (Halpern, 2003). The authors have broken Perry's model into four stages, with progression through the stages in a linear fashion. Perry's model can help educators understand how important aspects of critical thinking develop.

The first stage of Perry's (1968) model is called basic duality. This type of thinking is best illustrated by someone who believes there is only one truth and the authority of the truth is not to be questioned. Students who are functioning at this level will strictly memorize material with little critical thinking about the material. Some students in this stage will begin to question authority figures but will only identify those whom they believe are frauds. They will start to perceive information as limited truths. The second stage is called multiplicity pre-legitimate. A student's thinking about information changes from the notion that there is an absolute truth with correct/incorrect information to the notion that the truth remains to be known. At this stage, students' thinking processes change in that they understand that work is needed to provide evidence for opinions, including their own, for what may be the truth and that there may be multiple truths in the world.

List of Critical Thinking SkillsList of Critical Thinking SkillsILLUSTRATION BY GGS INFORMATION SERVICES. CENGAGE LEARNING, GALE.

The third stage is called relativism correlate, competing or diffuse. In this stage of development, students begin to understand that truth is contextual. Furthermore, they see that validity is an important issue that must be addressed in accepting that all knowledge may be relative but not equally valid. Another important aspect of the thinking process is the realization that theories are more like metaphors for the real world and are not to be accepted as absolute truths. With the realization of information being relative and the idea of validating information, students can become disoriented and starts to question the self. There is a realization that decisions need to be made in an uncertain world, a difficult process to go through. The final stage of Perry's model is called commitment foreseen. The students who reach this stage have come to the conclusion that commitments for how knowledge is obtained, used, and created needs to be made carefully.

The commitments made in the final stage influence personal values and career decisions. More importantly, students realize a balance must be made in assessing and accepting new information. Students become more flexible in respecting others' values and are aware that they must be open-minded and ready to learn new information while still maintaining their own values. The key element to this stage of thinking is that the student realizes that the process of acquiring, analyzing, and making a decision about new information is an iterative process. It is a process that requires much knowledge about one's own thinking while allowing for acquiring new information. This process has come to be known as metacognition.


Metacognitive processes are central to understanding critical thinking. John Flavell (1979) introduced four basic components to self-knowledge: metacognitive knowledge, metacognitive experiences, goals, and strategies. They are often referred to as ease of learning judgments. The ease of learning judgment is an initial assessment by the student of how easy or difficult it will be to acquire the new information. In making these judgments, critical thinkers will devise a plan for the best way to obtain new information. Critical thinkers also recognize the potential cognitive strategies and skills that may be required. The quality of learning judgment is a monitor of how well the information is being learned. Critical thinkers assess if any changes in their learning process need to be changed by using different cognitive strategies or skills. The feeling of knowing judgment is a check on how well information is known. During this time in the thinking process, critical thinkers will seek consensus to determine if information has been conceptualized correctly. If the information turns out to be false, critical thinkers are willing to self-correct.

The degree of confidence judgment is a monitor for how confident the student is in giving an answer. Many errors can occur in the process of making this judgment. Asher Koriat, Sarah Lichtenstein, and Baruch Fischhoff (1980) found that people are susceptible to ignoring evidence that contradicts their answers and tend to favor positive evidence when compared to negative evidence. It is crucial that students are willing to self-correct while judging how confident they are in a belief. Metacognition is an important component in the critical thinking process in that people need to be aware of their own knowledge in the cognitive strategies and skills that are at their disposal. It is during the process of thinking about their own thinking that students assess the quality of the data or other evidence that supports their conclusion and how closely related the data are to the conclusion.


The instruction of critical thinking has been transitioning from teaching students to critically think in a content driven course to courses designed exclusively to teach critical thinking. The latter approach allows the students to become explicitly aware of their thinking by providing them with both academic and real-world examples in demonstrating the cognitive strategies and skills associated with critical thinking. Halpern's taxonomy of critical thinking allows students to develop a critical thinker attitude by engaging in real-world, practical examples as opposed to the more traditional approach of dialectical reasoning.

Halpern's critical thinking taxonomy is designed from a skills based approach. The skills are broken down into ten primary categories as follows: critical thinking framework, memory, language and thought, reasoning, analyzing arguments, hypothesis testing, likelihood and uncertainty, decision making, problem solving skills, and creativity. The skills taught are geared toward the student becoming accustomed to thinking at the highest levels of Bloom's taxonomy, which include evaluating, designing, and creating knowledge.

The critical thinking framework includes the skills for framing the problem and recognizing the goal. Skills in memory include mnemonics and the recognition that memory is a mediator of thought. The relationship between language and thought is important for students to understand, and they need to gain skills in recognizing emotional language, the use of vagueness, ambiguity, and reification. Other basic skills include recognizing anchoring and framing effects, thinking in terms of probability and likelihood, and working backwards to find a solution to a problem.

Understanding arguments and the concept of hypothesis testing are both important for people to be effective critical thinkers. The skills that come in understanding arguments include recognizing the components of an argument and recognizing typical fallacies that people use in arguments. For hypothesis testing, the necessary skills include being able to distinguish between inductive and deductive reasoning, knowing the difference between an independent variable and dependent variable, and the importance of random assignment.

The accumulation and combination of these skills, along with many others, are what create a critical thinker. Critical thinking is not a single skill that can be used over and over in a rote fashion; this sort of conceptualization is antithetical to the very idea of a critical thinker. A critical thinker has the ability to use any and all strategies as appropriate and maybe even to create some new strategies in developing a solution to a problem.


There are two primary critical thinking assessments. The first assessment, the Watson-Glaser Critical Thinking Appraisal (WGCTA), is designed to evaluate a critical thinker's ability to solve problems, reason deductively, evaluate arguments, make inferences, and conduct interpretations. The second is the Halpern Critical Thinking Assessment (HCTA). Similar to Halpern's taxonomy, this assessment is designed to test students' critical thinking skills within the context of real-world situations. For example, test takers might be asked to evaluate an argument that if the Immigration Office changes one country's immigration quota, then it will have to change the immigration quota for all other countries. The objective of this particular example is to see if the person recognizes the slippery slope fallacy being used by the Immigration Office.

Critical thinking is a process that requires the conscious awareness of a person's ability to recognize the cognitive strategies and skills that he or she can use appropriately. Metacognition is the monitoring of one's own cognition and capabilities. In explicitly teaching students critical thinking strategies through a skills-based approach, they will be directed through the developmental stages of intellectual development. The result is a critically conscious citizen whose decisions will have a higher probability rate of being informed and judicious.


Dewey, J. (1916). Democracy and education: an introduction to the philosophy of education. New York: Macmillan. Retrieved April 18, 2008 from

Flavell, J. H. (1979). Metacognition and cognitive monitoring: a new area of cognitive-developmental inquiry. American Psychologist, 34(10), 906–911.

Halpern, D. F. (2007). The nature and nurture of critical thinking. In R. Sternberg, R. Roediger, & D. F. Halpern (Eds.). Critical Thinking in Psychology (pp. 1–14). Cambridge, MA: Cambridge University Press.

Halpern, D. F. (2003) Thought and knowledge: An introduction to critical thinking. Mahwah, NJ: Erlbaum.

Koriat, A., Lichtenstein, S., & Fischhoff, B. (1980). Reasons for confidence. Journal of Experimental Psychology: Human Learning and Memory, 6(2), 107–118.

Perry, W. G. (1968). Forms of intellectual and ethical development: in the college years. New York: Holt, Rinehart and Winston.

Shepard, R. N., & Metzler, J. (1971). Mental rotation of three-dimensional objects. Science, 171(3972), 701–703.