In this paper, it is argued that the most fruitful approach to developing normative models of argument quality is one that combines the argumentation scheme approach with Bayesian argumentation. Three sample argumentation schemes from the literature are discussed: the argument from sign, the argument from expert opinion, and the appeal to popular opinion. Limitations of the scheme-based treatment of these argument forms are identified and it is shown how a Bayesian perspective may help to overcome these. At the same time, (...) the contributions of the standard scheme-based approach are highlighted, and it is argued that only a combination of the insights of different traditions will yield a complete normative theory of argument quality. (shrink)

Being able to discriminate poorly justified from well justified arguments is necessary for informed citizenship. However, it is not known whether the ability to recognize argument strength generalizes across different types of arguments, and what cognitive factors predict this ability or these abilities. Drawing on the theory of argument schemes, we examined arguments from consequence, analogy, symptoms, and authority in order to cover all major types of arguments. A study (_N_ = 278) on the general population in Finland indicated that (...) the ability to discriminate between strong and weak arguments did not differ between these schemes. Argument strength discrimination ability correlated positively with analytic thinking dispositions promoting both quality and quantity of thinking, slightly positively with education, and negatively with overconfidence. It was unrelated to an intuitive thinking style, and to self-rated mental effort. (shrink)

Overestimation of one’s ability to argue their position on socio-political issues may partially underlie the current climate of political extremism in the U.S. Yet very little is known about what factors influence overestimation in argumentation of socio-political issues. Across three experiments, emotional investment substantially increased participants’ overestimation. Potential confounding factors like topic complexity and familiarity were ruled out as alternative explanations. Belief-based cues were established as a mechanism underlying the relationship between emotional investment and overestimation in a measurement-of-mediation and manipulation-of-mediator (...) design. Representing a new bias blind spot, participants believed emotional investment helps them argue better than it helps others ; where in reality emotional investment harmed or had no effect on argument quality. These studies highlight misguided beliefs about emotional investment as a factor underlying metacognitive miscalibration in the context of socio-political issues. (shrink)

Can argumentation schemes play a part in the critical processing of argumentation by lay people? In a qualitative study, participants were invited to come up with strong and weak arguments for a given claim and were subsequently interviewed for why they thought the strong argument was stronger than the weak one. Next, they were presented with a list of arguments and asked to rank these arguments from strongest to weakest, upon which they were asked to motivate their judgments in an (...) interview. In order to assess whether lay people apply argument scheme specific criteria when performing these tasks, five different argumentation schemes were included in this study: argumentation from authority, from example, from analogy, from cause to effect, and from consequences. Laypeople’s use of criteria for argument quality was inferred from interview protocols. The results revealed that participants combined general criteria from informal logic and scheme-specific criteria. The results supported the conventional validity of the pragma-dialectical argument scheme rule in a strong sense and provided a more fine-grained view of central processing in the Elaboration Likelihood Model. (shrink)

How people distinguish well-justified from poorly justified arguments is not well known. To study the involvement of intuitive and analytic cognitive processes, we contrasted participants’ personal beliefs with argument strength that was determined in relation to established criteria of sound argumentation. In line with previous findings indicating that people have a myside bias, participants (N = 249) made more errors on conflict than on no-conflict trials. On conflict trials, errors and correct responses were practically equal in terms of response times (...) and mouse-tracking indices of hesitation. Similarly to recent findings on formal reasoning, these findings indicate that correct reasoning about informal arguments may not necessitate corrective analytic processing. We compared findings across four argument schemes but found few differences. The findings are discussed in light of intuitive logic theories and the notion that evaluating informal arguments could be based on implicit knowledge of argument criteria. (shrink)

Many experiments suggest that participants are more critical of arguments that challenge their views or that come from untrustworthy sources. However, other results suggest that this might not be true of demonstrative arguments. A series of four experiments tested whether people are influenced by two factors when they evaluate demonstrative arguments: how confident they are in the answer being challenged by the argument, and how much they trust the source of the argument. Participants were not affected by their confidence in (...) the answer challenged by the argument. By contrast, they were sometimes affected by their trust in the argument’s source. Analyses of reaction times and transfer problems suggest that source trustworthiness did not directly affect argument evaluation, but affected instead the number of times the participants considered the arguments. Our results thus suggest that people can evaluate demonstrative arguments objectively. In conclusion, we defend the hypothesis that people might also be able to evaluate non-demonstrative arguments objectively. These results support the predictions of the argumentative theory of reasoning. (shrink)