Critical thinking is the objective analysis of facts to form a judgment. The subject is complex, and there are several different definitions which generally include the rational, skeptical, unbiased analysis or evaluation of factual evidence.
Critical thinking was described by Richard W. Paul as a movement in two waves (1994). The "first wave" of critical thinking is often referred to as a 'critical analysis' that is clear, rational thinking involving critique. Its details vary amongst those who define it. According to Barry K. Beyer (1995), critical thinking means making clear, reasoned judgments. During the process of critical thinking, ideas should be reasoned, well thought out, and judged. The U.S. National Council for Excellence in Critical Thinking defines critical thinking as the "intellectually disciplined process of actively and skillfully conceptualizing, applying, analyzing, synthesizing, or evaluating information gathered from, or generated by, observation, experience, reflection, reasoning, or communication, as a guide to belief and action."
In the term critical thinking, the word critical, (Grk. = kritikos = "critic") derives from the word critic and implies a critique; it identifies the intellectual capacity and the means "of judging", "of judgement", "for judging", and of being "able to discern".
Traditionally, critical thinking has been variously defined as:
Contemporary critical thinking scholars have expanded these traditional definitions to include qualities, concepts, and processes such as creativity, imagination, discovery, reflection, empathy, connecting knowing, feminist theory, subjectivity, ambiguity, and inconclusiveness. Some definitions of critical thinking exclude these subjective practices.
The ability to reason logically is a fundamental skill of rational agents, hence the study of the form of correct argumentation is relevant to the study of critical thinking.
"First wave" logical thinking consisted of understanding the connections between two concepts or points in thought. It followed a philosophy where the thinker was removed from the train of thought and the connections and the analysis of the connect was devoid of any bias of the thinker. Kerry Walters describes this ideology in his essay Beyond Logicism in Critical Thinking, "A logistic approach to critical thinking conveys the message to students that thinking is legitimate only when it conforms to the procedures of informal (and, to a lesser extent, formal) logic and that the good thinker necessarily aims for styles of examination and appraisal that are analytical, abstract, universal, and objective. This model of thinking has become so entrenched in conventional academic wisdom that many educators accept it as canon" (Walters, 1994, p. 1). The adoption of these principals parallel themselves with the increasing reliance on quantitative understanding of the world.
In the 'second wave' of critical thinking, as defined by Kerry S. Walters (Re-thinking Reason, 1994, p. 1 ), many authors moved away from the logocentric mode of critical thinking that the 'first wave' privileged, especially in institutions of higher learning. Walters summarizes logicism as "the unwarranted assumption that good thinking is reducible to logical thinking" (1994, p. 1).
"A logistic approach to critical thinking conveys the message to students that thinking is legitimate only when it conforms to the procedures of informal (and, to a lesser extent,, formal) logic and that the good thinker necessarily aims for styles of examination and appraisal that are analytical, abstract, universal, and objective." (Walters, 1994, p. 1) As the 'second wave' took hold, scholars began to take a more inclusive view of what constituted as critical thinking. Rationality and logic are still widely accepted in many circles as the primary examples of critical thinking.
Inductive thinking involves drawing on many different facts, concepts, or opinions to come to a larger conclusion. Examples of inductive reasoning include differential diagnosis, inquiry-based education, and trial and error. Deductive Reasoning involves addressing the known first, and attempt to discover more information about why the known is what it is. Examples of deductive reasoning include root cause analysis and top down learning.
Kerry S. Walters (Re-thinking Reason, 1994) argues that rationality demands more than just logical or traditional methods of problem solving and analysis or what he calls the "calculus of justification" but also considers "cognitive acts such as imagination, conceptual creativity, intuition and insight" (p. 63). These "functions" are focused on discovery, on more abstract processes instead of linear, rules-based approaches to problem solving. The linear and non-sequential mind must both be engaged in the rational mind.
The ability to critically analyze an argument - to dissect structure and components, thesis and reasons - is important. But so is the ability to be flexible and consider non-traditional alternatives and perspectives. These complementary functions are what allow for critical thinking a practice encompassing imagination and intuition in cooperation with traditional modes of deductive inquiry.
The list of core critical thinking skills includes observation, interpretation, analysis, inference, evaluation, explanation, and metacognition. According to Reynolds (2011), an individual or group engaged in a strong way of critical thinking gives due consideration to establish for instance:
In addition to possessing strong critical-thinking skills, one must be disposed to engage problems and decisions using those skills. Critical thinking employs not only logic but broad intellectual criteria such as clarity, credibility, accuracy, precision, relevance, depth, breadth, significance, and fairness.
Critical thinking calls for the ability to:
"A persistent effort to examine any belief or supposed form of knowledge in the light of the evidence that supports or refutes it and the further conclusions to which it tends."
The habits of mind that characterize a person strongly disposed toward critical thinking include a desire to follow reason and evidence wherever they may lead, a systematic approach to problem solving, inquisitiveness, even-handedness, and confidence in reasoning.
According to a definition analysis by Kompf & Bond (2001), critical thinking involves problem solving, decision making, metacognition, rationality, rational thinking, reasoning, knowledge, intelligence and also a moral component such as reflective thinking. Critical thinkers therefore need to have reached a level of maturity in their development, possess a certain attitude as well as a set of taught skills.
Edward M. Glaser proposed that the ability to think critically involves three elements:
Educational programs aimed at developing critical thinking in children and adult learners, individually or in group problem solving and decision making contexts, continue to address these same three central elements.
The Critical Thinking project at Human Science Lab, London, is involved in scientific study of all major educational system in prevalence today to assess how the systems are working to promote or impede critical thinking.
Contemporary cognitive psychology regards human reasoning as a complex process that is both reactive and reflective.
The relationship between critical thinking skills and critical thinking dispositions is an empirical question. Some people have both in abundance, some have skills but not the disposition to use them, some are disposed but lack strong skills, and some have neither. A measure of critical thinking dispositions is the California Measure of Mental Motivation.
Critical thinking is significant in academics due to being significant in learning. Critical thinking is significant in the learning process of internalization, in the construction of basic ideas, principles, and theories inherent in content. And critical thinking is significant in the learning process of application, whereby those ideas, principles, and theories are implemented effectively as they become relevant in learners' lives.
Each discipline adapts its use of critical thinking concepts and principles. The core concepts are always there, but they are embedded in subject-specific content. For students to learn content, intellectual engagement is crucial. All students must do their own thinking, their own construction of knowledge. Good teachers recognize this and therefore focus on the questions, readings, activities that stimulate the mind to take ownership of key concepts and principles underlying the subject.
Historically, teaching of critical thinking focused only on logical procedures such as formal and informal logic. This emphasized to students that good thinking is equivalent to logical thinking. However, a second wave of critical thinking, urges educators to value conventional techniques, meanwhile expanding what it means to be a critical thinker. In 1994, Kerry Walters compiled a conglomeration of sources surpassing this logical restriction to include many different authors' research regarding connected knowing, empathy, gender-sensitive ideals, collaboration, world views, intellectual autonomy, morality and enlightenment. These concepts invite students to incorporate their own perspectives and experiences into their thinking.
In the English and Welsh school systems, Critical Thinking is offered as a subject that 16- to 18-year-olds can take as an A-Level. Under the OCR exam board, students can sit two exam papers for the AS: "Credibility of Evidence" and "Assessing and Developing Argument". The full Advanced GCE is now available: in addition to the two AS units, candidates sit the two papers "Resolution of Dilemmas" and "Critical Reasoning". The A-level tests candidates on their ability to think critically about, and analyze, arguments on their deductive or inductive validity, as well as producing their own arguments. It also tests their ability to analyze certain related topics such as credibility and ethical decision-making. However, due to its comparative lack of subject content, many universities do not accept it as a main A-level for admissions. Nevertheless, the AS is often useful in developing reasoning skills, and the full Advanced GCE is useful for degree courses in politics, philosophy, history or theology, providing the skills required for critical analysis that are useful, for example, in biblical study.
There used to also be an Advanced Extension Award offered in Critical Thinking in the UK, open to any A-level student regardless of whether they have the Critical Thinking A-level. Cambridge International Examinations have an A-level in Thinking Skills.
OCR exam board have also modified theirs for 2008. Many examinations for university entrance set by universities, on top of A-level examinations, also include a critical thinking component, such as the LNAT, the UKCAT, the BioMedical Admissions Test and the Thinking Skills Assessment.
In Qatar, critical thinking was offered by AL-Bairaq which is an outreach, non-traditional educational program that targets high school students and focuses on a curriculum based on STEM fields. The idea behind AL-Bairaq is to offer high school students the opportunity to connect with the research environment in the Center for Advanced Materials (CAM) at Qatar University. Faculty members train and mentor the students and help develop and enhance their critical thinking, problem-solving, and teamwork skills.[not in citation given]
In 1995, a meta-analysis of the literature on teaching effectiveness in higher education was undertaken. The study noted concerns from higher education, politicians and business that higher education was failing to meet society's requirements for well-educated citizens. It concluded that although faculty may aspire to develop students' thinking skills, in practice they have tended to aim at facts and concepts utilizing lowest levels of cognition, rather than developing intellect or values.
In a more recent meta-analysis, researchers reviewed 341 quasi- or true-experimental studies, all of which used some form of standardized critical thinking measure to assess the outcome variable. The authors describe the various methodological approaches and attempt to categorize the differing assessment tools, which include standardized tests (and second-source measures), tests developed by teachers, tests developed by researchers, and tests developed by teachers who also serve the role as the researcher. The results emphasized the need for exposing students to real-world problems and the importance in encouraging open dialogue within a supportive environment. Effective strategies for teaching critical thinking are thought to be possible in a wide variety of educational settings.
Critical thinking is an important element of all professional fields and academic disciplines (by referencing their respective sets of permissible questions, evidence sources, criteria, etc.). Within the framework of scientific skepticism, the process of critical thinking involves the careful acquisition and interpretation of information and use of it to reach a well-justified conclusion. The concepts and principles of critical thinking can be applied to any context or case but only by reflecting upon the nature of that application. Critical thinking forms, therefore, a system of related, and overlapping, modes of thought such as anthropological thinking, sociological thinking, historical thinking, political thinking, psychological thinking, philosophical thinking, mathematical thinking, chemical thinking, biological thinking, ecological thinking, legal thinking, ethical thinking, musical thinking, thinking like a painter, sculptor, engineer, business person, etc. In other words, though critical thinking principles are universal, their application to disciplines requires a process of reflective contextualization.
 However, even with knowledge of the methods of logical inquiry and reasoning, mistakes can happen due to a thinker's inability to apply the methods or because of character traits such as egocentrism. Critical thinking includes identification of prejudice, bias, propaganda, self-deception, distortion, misinformation, etc. Given research in cognitive psychology, some educators believe that schools should focus on teaching their students critical thinking skills and cultivation of intellectual traits.
Critical thinking skills can be used to help nurses during the assessment process. Through the use of critical thinking, nurses can question, evaluate, and reconstruct the nursing care process by challenging the established theory and practice. Critical thinking skills can help nurses problem solve, reflect, and make a conclusive decision about the current situation they face. Critical thinking creates "new possibilities for the development of the nursing knowledge." Due to the sociocultural, environmental, and political issues that are affecting healthcare delivery, it would be helpful to embody new techniques in nursing. Nurses can also engage their critical thinking skills through the Socratic method of dialogue and reflection. This practice standard is even part of some regulatory organizations such as the College of Nurses of Ontario - Professional Standards for Continuing Competencies (2006). It requires nurses to engage in Reflective Practice and keep records of this continued professional development for possible review by the College.
Critical thinking is also considered important for human rights education for toleration. The Declaration of Principles on Tolerance adopted by UNESCO in 1995 affirms that "education for tolerance could aim at countering factors that lead to fear and exclusion of others, and could help young people to develop capacities for independent judgement, critical thinking and ethical reasoning."
Critical thinking is used as a way of deciding whether a claim is true, partially true, or false. It is a tool by which one can come about reasoned conclusions based on a reasoned process.
The advent and rising popularity of online courses has prompted some to ask if computer-mediated communication (CMC) promotes, hinders, or has no effect on the amount and quality of critical thinking in a course (relative to face-to-face communication). There is some evidence to suggest a fourth, more nuanced possibility: that CMC may promote some aspects of critical thinking but hinder others. For example, Guiller et al. (2008) found that, relative to face-to-face discourse, online discourse featured more justifications, while face-to-face discourse featured more instances of students expanding on what others had said. The increase in justifications may be due to the asynchronous nature of online discussions, while the increase in expanding comments may be due to the spontaneity of 'real time' discussion. Newman et al. (1995) showed similar differential effects. They found that while CMC boasted more important statements and linking of ideas, it lacked novelty. The authors suggest that this may be due to difficulties participating in a brainstorming-style activity in an asynchronous environment. Rather, the asynchrony may promote users to put forth "considered, thought out contributions."
Researchers assessing critical thinking in online discussion forums often employ a technique called Content Analysis, where the text of online discourse (or the transcription of face-to-face discourse) is systematically coded for different kinds of statements relating to critical thinking. For example, a statement might be coded as "Discuss ambiguities to clear them up" or "Welcoming outside knowledge" as positive indicators of critical thinking. Conversely, statements reflecting poor critical thinking may be labeled as "Sticking to prejudice or assumptions" or "Squashing attempts to bring in outside knowledge." The frequency of these codes in CMC and face-to-face discourse can be compared to draw conclusions about the quality of critical thinking.
Searching for evidence of critical thinking in discourse has roots in a definition of critical thinking put forth by Kuhn (1991), which places more emphasis on the social nature of discussion and knowledge construction. There is limited research on the role of social experience in critical thinking development, but there is some evidence to suggest it is an important factor. For example, research has shown that 3- to 4-year-old children can discern, to some extent, the differential creditability and expertise of individuals. Further evidence for the impact of social experience on the development of critical thinking skills comes from work that found that 6- to 7-year-olds from China have similar levels of skepticism to 10- and 11-year-olds in the United States. If the development of critical thinking skills was solely due to maturation, it is unlikely we would see such dramatic differences across cultures.