Critical thinking skill is exemplified by asking questions
about alternative possibilities in order to reliably
achieve some objective. Asking and answering questions
is a skill of dialogue. Alternative possibilities are represented
by mental models. A process of questioning mental models is
(or should be) adopted because of its reliability for achieving
the purposes of the participants within the available time.
Thus, the theory of critical thinking draws on and synthesizes
research on three separate topics:
1. Theories of reasoning according to which people represent
information about a problem or situation by means of mental
models of alternative possibilities, evaluate the models in
the light of relevant background knowledge, update the models
by adding new information as it becomes available, revise
models to resolve internal inconsistencies, and draw conclusions
by inspecting the surviving possibilities (adapted from Johnson-Laird,
1983; Johnson-Laird & Byrne, 1991).
2. Theories of critical discussion in which a proponent must
defend a claim against challenges of various kinds by an opponent
or critic (adapted from Rescher, 1977; Walton & Krabbe,
1995; van Eemeren & Grootendorst, 1992; Walton, 1998).
3. Theories of the cognitive mechanisms and processes involved
in belief formation and decision making, which vary in their
reliability or their association with proficient performance
in a domain (adapted from Simon, 1997; Gigerenzer & Selten,
2001; Ericsson & Smith, 1991; Klein et al., 1993; Payne,
Bettman, & Johnson, 1993).
Critical thinking has a multi-layered structure . The three
aspects of the theory form a spectrum from internal ratinality
or coherence (mental model theory) to intersubjective dialogue
to correspondence with external reality (reliability). The
concept of critical thinking as internal or external dialogue
forms the crucial brdige.
A model of critical thinking with three embedded layers:
mental models, critical dialogue, and control based on reliability.
All three of these aspects involve both empirical and normative
elements. In particular, each of the three layers is associated
with distinctive criteria of performance, which progress from
internal to external in their focus:
1. At its innermost core critical thinking involves representation
of alternative possible states of affairs, or mental models.
The key metric of performance at this level is the explanatory
coherence of mental models and the coherence between mental
models and background beliefs. Errors occur when cognizers
overlook alternative possibilities or fail to properly assess
the relative plausibility of different mental models, including
their comprehensiveness and simplicity as explanations.
2. At the intermediate level, mental models are embedded within
a layer of critical questioning which motivates the generation
and evaluation of possibilities. Critical questioning may
take place within a single mind among different individuals,
but is evaluated by reference to norms for conducting the
appropriate kinds of critical dialogue. Dialogue types are
differentiated by the purposes they serve, by the types of
challenges that are permitted to the opponent, and the scope
of the permitted responses by the proponent. At this level
of analysis, errors occur when cognizers fail to ask or answer
questions associated with the appropriate argumentation scheme,
use argumentation schemes that obstruct the purpose of the
dialogue, or inappropriately shift from one dialogue type
to another (Walton, 1998).
3. At the outermost layer, critical thinking is a judgment
about the reliability of a cognitive process or faculty, hence,
the degree of trust that should be placed in its outputs.
A critical dialogue is only one of various cognitive or social
processes that might be utilized alone or in combination to
generate beliefs and decisions. Non-deliberative processes,
such as pattern recognition, may be more reliable under some
conditions and can almost always be used to verify the results
of reasoning - just as reasoning is used to check the results
of intuition. At this level, errors occur when cognizers use
inappropriate or inefficient strategies, and when they terminate
a process too soon or continue it too long.
In sum, critical thinking skill is exemplified by asking and
answering critical questions about alternative possible states
of affairs, with the intent of achieving the purpose of an