This glossary may be thought of as a subset of the concepts and ideas that we would expect all educated people to be familiar with, regardless of their fields of specialization.

An important character of critical thinking is the room that it provides for doubting, questioning, and disagreeing. True to this attitude, the clarification of each of the concepts in this glossary allows itself to be subjected to critical thinking. As an explicit acknowledgement of this value system, each of the entries below has a link to agreements and disagreements, containing and/or inviting not only additional entries that provide extensions and supporting views, but also objections and alternative points of view. Each of the entries under disagreements in turn is linked to agreements and disagreements, thereby providing a branching structure of potentially never ending series.

We invite the readers to participate in the growth of this website by contributing write ups of either new topics or disagreements. Please e-mail your contributions to .

What is critical thinking? (contributed by K P Mohanan)

An e-dialogue on critical and creative thinking (contributed by C M Wang and K P Mohanan)

Ingredients of critical thinking (contributed by K P Mohanan)

The mindset of critical thinking (contributed by K P Mohanan)

The meanings of ‘critical’ in critical thinking

Critical thinking as the evaluation of claims (e.g., evaluating knowledge claims)
Critical thinking as the evaluation of quality (e.g., evaluating teaching quality)
Critical thinking as pointing out flaws (e.g., criticizing society)

Claims and conclusions

What is a claim?
Claims, grounds, and reasoning

Justification of claims

What is justification?
Structure of justification: grounds, reasoning, criteria and conclusions
Types of grounds: definitions and axioms, experience, observation
Types of justification: axiomatic, empirical, introspective, semi-subjective
Types of observation: quantitative, qualitative, experimental, non-experimental
Soundness of justification
Justification and argumentation
Justification and proof
Justification and evidence

Evidence

What is evidence? (contributed by K P Mohanan)
Types of evidence
Evidence and other types of grounds

Reasoning

What is reasoning? (contributed by K P Mohanan)
Logic and reasoning
        Rules of inference (contributed by K P Mohanan)
Types of reasoning
        Inductive Reasoning (contributed by K P Mohanan)
Classical and non-classical logics
Validity of reasoning

Argumentation

What is an argument?
Proof vs. defeasible argumentation
Epistemological and rhetorical aspects of argumentation

Value systems and criteria of evaluation

Canons of rational inquiry
Canons of scientific inquiry (as part of rational inquiry)
Canons of mathematical inquiry (as part of rational inquiry)

Critical reading and critical understanding

What is critical reading?
What is critical understanding?

Concepts of statistical inquiry relevant for CT

Making inferences on population on the basis of a sample
Variability and distribution
Sample size, representativeness of the sample, anecdotal evidence
Mean, mode, and median
Standard deviation, standard error, and significance
Correlations

Concepts of experimental inquiry relevant for CT

Variables and correlations
Independent and dependent variables, confounded variables, controlling for variables
Operationalization
Correlations vs. (causal) explanations
Language and Critical thinking

Words and sentences vs concepts and propositions

Logic and language
Equivocation
Clarification of concepts