The objectives of the research were (i) to develop a general analytical framework for understanding critical thinking and evaluating alternative approaches, and (ii) to outline a new, integrative theory of critical thinking based on that understanding. These objectives are reflected in Parts I and II of the report, respectively.

In pursuit of the first objective, we reviewed the literature in critical thinking and in fields from which it draws such as informal logic, epistemology, logic, decision making, and cognitive psychology. In Part I we addressed a series of issues:

• What claims are made for the utility of critical thinking? What obstacles stand in the way of realizing that utility? (Chapter 1)
  
  
• What does it mean to define critical thinking? What types of definition are possible? (Chapter 3)
  
  
• How has critical thinking in fact been defined? What are the shared and non-shared features of current definitions? (Chapter 4, Appendix A)
  
  
• What are the major differences in underlying assumptions in approaches to critical thinking? What implications do these differences have for the shape of a critical thinking theory? (Chapter 5)
  
  
• What specific critical thinking paradigms have been proposed? How do they vary? (Chapter 6)
  
  
• What are the detailed strengths and weaknesses of informal logic as a component of critical thinking? (Appendix B)

The framework that emerged from these questions guided our work on the second objective, the development of an integrated theory of critical thinking. In Part II, we do the following:

• Lay out a theory of critical thinking (Chapter 7)
  
  
• Make a case for the new theory by analyzing its relationship to traditional and contemporary theories of knowledge and reasoning (Chapters 8, 9, and 10; Appendix B)
  
  
• Apply the new theory to the problem of training and assessing critical thinking skills in teams (Chapter 11)
  
  
• Evaluate the usefulness of critical thinking training in the Army battlefield domain in light of the new theory (Chapter 12).

In Part I, we reach the following conclusions:

• It is often claimed that critical thinking skills have grown in importance as a result of increased problem complexity, decentralization of organizational structure, and more frequent high stakes decisions. In the Army battlefield context, however, doubts about its usefulness arise due to potential demands on time and training resources, and the possibility that it will stifle innovation or dilute the effects of leadership and experience. (Chapter 1)
  
  
• There are three complementary levels at which critical thinking can be studied and defined: normative, cognitive, and applied. The cognitive level can be divided into processes, mechanisms, and their interaction via cognitive faculties. Each of these levels affects the others in important ways (Chapter 3)
  
  
• Definitions of critical thinking in the literature vary in part because of their varying emphasis on normative, cognitive process, cognitive mechanism, and applied levels. A common core of current definitions might be that critical thinking is the deliberate evaluation of intellectual products in terms of a standard. Definitions vary with respect to the products to be evaluated, the standards to be used, and the processes and mechanisms that carry the evaluation out. (Chapter 4)
  
  
• These differences can largely be accounted for in terms of the competition between two high-level paradigms. Critical thinking has traditionally been conceptualized from an internalist point of view, which sees it as taking place within the consciousness of an individual. Rational justification consists in the evaluation of a static set of beliefs through the application of universal (e.g., logical) standards. Cognitive processes and strategies are unimportant since only the information present in the mind at one time is relevant.
  
  From the externalist point of view, by contrast, evaluation is a matter of estimating the reliability in a real environment of the cognitive processes that produced an intellectual product. Externalist evaluation is highly context-dependent, the relevant processes may be domain-specific, and intellectual products other than beliefs may also be critically evaluated. Cognitive processes that identify biases and fallacies, expose views to challenge, and actively seek information may increase overall reliability in particular circumstances., But critical thinking is not necessary for rationality: In some circumstances, intuitive or recognitional processes may be more reliable. From the externalist point of view, critical thinking skill includes not only cognitive processes, but also enduring traits or dispositions to adaptively select strategies that have proven reliable. (Chapter 5)
  
  
• Mid-level paradigms for critical thinking include approaches like operations research, decision theory, formal logic, informal logic, dialogue theory, bounded rationality, naturalistic decision making, and rhetoric. Differences among these can be understood along two dimensions: whether they admit the relevance of how people actually make decisions to judgments of how they ought to make decisions, and whether they adopt an externalist or internalist stance toward the grounds for an evaluative judgment. (Chapter 6)

In Part II, we reach these conclusions:

• We describe a theory of critical thinking that integrates elements of internalist and externalist paradigms in a consistent way. Critical thinking skill requires coordination of three different perspectives: proponent, opponent, and judge. To understand these three different roles, the theory draws on and synthesizes research in three areas: (1) Cognitive theories according to which alternative possibilities are represented by mental models and reasoning is accomplished by manipulating mental models. (2) Normative models of critical discussion in which a proponent must defend a claim against challenge by an opponent or critic. (3) Assessments by a judge about the reliability of cognitive processes for achieving external purposes. Dialogue theory provides a bridge between internal and external points of view, since critical thinking dialogues take place within an individual or among different individuals. (Chapter 7)
  
  
• Standard approaches to critical thinking are heavily influenced by classical and contemporary foundationalism, the view that knowledge is built up cumulatively one step at a time from solid foundations. From the point of view of our theory, this approach places constraints on critical dialogue that are not always appropriate. Traditional views unduly constrain critical thinking dialogue. (Chapter 8) A detailed examination of informal logic provides support for this conclusion. (Appendix B)
  
  
• Mental models, or stories, as well as network models of underlying knowledge, are central to a more realistic understanding of critical thinking. Stories and mental models are evaluated in part in terms of coherence. Ultimately coherence can be analyzed in terms of the number and nature of the questions a story answers. Coherent models must be built and maintained by highly flexible question and answer strategies in critical dialogue. (Chapter 9)
  
  
• Ultimately, the value of a critical thinking strategy is determined by its success in achieving real-world goals under the relevant conditions. Instead of viewing the process "from the inside" (e.g., what reasons do I have for this conclusion? Can I answer this objection?), the external point of view looks more generally at the record of success of this type of strategy in similar circumstances in the past. Both points of view are necessary, and they complement one another. The external point of view determines what cognitive strategy or dialogue type is appropriate and when and how it should be terminated and a decision reached. Problems with the externalist framework can be handled by acknowledging that it reflects a task-relative point of view. (Chapter 10)
  
  
• Team decision making depends on shared mental models of the task, the situation, and the communicative processes within the team that create and maintain such shared knowledge. A key practical application of the critical thinking theory, therefore, is to team decision making. Rules for the conduct of each stage of critical discussion, taken together, provide a normative model for team problem solving. The theory can be used to develop training objectives, training content, and assessment measures. (Chapter 11)
  
  
• The critical thinking theory provides preliminary answers to challenges raised in Chapter 1. The theory provides two crucial types of flexibility: (i) There is an array of dialogue types that differ in the intensity with which underlying assumptions are probed and which are suited to different contexts. (ii) The judge, adopting an external point of view, determines what strategy will most reliably achieve the real-world objective, including among the options non-deliberative processes such as recognition-based decision making. (Chapter 12)

An adequate theory of critical thinking, with both theoretical and applied dimensions, is a key condition of progress in the development of critical thinking training and support. Such a theory is needed to guide the application of critical thinking principles to Army battlefield contexts as well as to a variety of other domains.

The new theory of critical thinking combines theoretical soundness with practical utility. At the practical level, it lends itself directly to operationalization: concrete specification of the practices that make up successful critical thinking in different contexts. These specifications in turn serve as the objectives of critical thinking training or decision support. Each of the three components brings with it criteria for success and methods for the identification of errors. The theory should help us specify critical thinking objectives, develop training material, and measure success. The ultimate result should be better decision making by both individuals and teams.