When people claim that something is the case, how do they know? What justification do they regard as sufficient to warrant making the claim and sufficient to demonstrate its correctness if asked to do so? Young children have little awareness of how they know what they know (Kuhn & Pearsall, 2000). How much better are teens or adults in this respect? These meta-level skills warrant the attention of educators.

In addition to learning how to manage and monitor the acquisition of new knowledge (IV, V), by means of meta-level processes, it is important to learn how to manage and monitor the products of knowledge acquisition: all of the knowledge and beliefs that one takes to be true. This means applying similar meta-level processes to manage one's declarative knowing (knowing that), as well as procedural knowing (knowing how). Knowing about one's declarative knowing means knowing how one knows something is so and being able to justify one's claims.

Just as young children confuse theory and evidence in justifying simple event claims (Kuhn & Pearsall, 2000), older children, teens, and even adults may confuse theory and evidence in justifying causal claims, i.e., claims that a particular antecedent factor has contributed to an outcome. Causal claims are sometimes justified by explanations that make them seem plausible. Or they may be justified by evidence indicating that the causal effect in fact occurs. Both kinds of justifications have a contribution to make in supporting causal claims. And each has its associated strengths and weaknesses. Explanation offers understanding, but may be false. Evidence offers truth, but fails to explain. Critical for education for thinking to promote is meta-level understanding of these epistemological strengths and weaknesses of the two kinds of justifications.

Kuhn and Felton (2000) asked eighth graders, community college students, and beginning graduate students to choose the stronger of two arguments in support of a claim. One argument provides a theoretical explanation that makes the claim plausible, while the other provides empirical evidence that the claim is true (see example). More important than the choice students make, however, are the reasons they give for their choices. They were asked to indicate the strengths of the argument they chose and the weaknesses of the other argument. They were also asked if the chosen argument had any weaknesses and the other argument any strengths.

Although older and more educated students did better, few students exhibited understanding of the epistemic strengths and weaknesses of each argument type -- that is, characteristics that pertain to the form of the argument, rather than its content. Epistemic characteristics apply to any argument of its form; non-epistemic characteristics may not extend beyond the particular argument being considered. Participants' non-epistemic responses most often addressed the correctness of the claim (e.g., "This is a good argument because I think what it's saying is true"), rather than the quality of the argument supporting the claim. Overall, less than half of participants in this study were able to cite the epistemic strengths and weaknesses of evidence vs. explanation. Performance levels varied by argument type and participant group.

Why is the ability to justify claims so important as to be a core objective of education for thinking (VIII)? People who know how they know all that they know to be true are in control of their own knowing. They understand what support must be in place to justify a claim and what kinds of counterevidence disprove it. They are thus open to change of belief in the face of new evidence and argument, but their beliefs do not fluctuate in reaction to every new influence. To be in control of their own knowing and thinking may be the most important way in which people, individually and collectively, take control of their lives.

Sources for further reading:

Kuhn, D. (2001). How do people know? Psychological Science, 12 (1).

Kuhn, D., & Felton, M. (2000). Developing appreciation of the relevance of evidence to argument. Paper presented at the Winter Conference on Discourse, Text, and Cognition, Jackson Hole WY. [See Kuhn, D. (2001). How do people know? Psychological Science, 12 (1), for summary.]

Kuhn, D., & Pearsall, S. (2000). Developmental origins of scientific thinking. Journal of Cognition and Development, 1, 113-129.