According to Mercier and Sperber (2009, 2011, 2017), people have an immediate and intuitive feeling about the strength of an argument. These intuitive evaluations are not captured by current evaluation methods of argument strength, yet they could be important to predict the extent to which people accept the claim supported by the argument. In an exploratory study, therefore, a newly developed intuitive evaluation method to assess argument strength was compared to an explicit argument strength evaluation method (the PAS scale; Zhao et al., 2011), on their ability to predict claim acceptance (predictive validity) and on their sensitivity to differences in the manipulated quality of arguments (construct validity). An experimental study showed that the explicit argument strength evaluation performed well on the two validity measures. The intuitive evaluation measure, on the other hand, was not found to be valid. Suggestions for other ways of constructing and testing intuitive evaluation measures are presented.
Hornikx, J., Weerman, A., & Hoeken, H. (2022). An exploratory test of an intuitive evaluation method of perceived argument strength. Studies in Communication Sciences, 22 (2), 311-324. [link]
Empirical research has shown that high-quality arguments according to criteria from argumentation theory lead to higher claim acceptance than low-quality arguments. However, this relationship was not observed in some cultural settings. This leads to the question whether criteria for high-quality arguments are culturally variable or universal. Therefore, adding to existing research on sensitivity to quality criteria for the argument from authority and the argument from generalization conducted mainly in Western cultural contexts, an experiment was run in Turkey (N = 307). Results showed that Turkish participants were sensitive to the quality of arguments: claim acceptance was higher when high-quality variants were used than when low-quality variants were used. While not neglecting potential cultural variability, these data add to the findings that there might be some level of universality in sensitivity to criteria for argument quality.
Demir, Y., & Hornikx, J. (2022). Sensitivity to argument quality: Adding Turkish data to the question of cultural variability versus universality. Communication Research Reports, 39 (2), 104-113. [link]
During the COVID-19 pandemic, people around the world were bombarded by new information, often provided by experts, such as epidemiologists, virologists, or intensive care specialists. These experts have struggled at convincing the general public to behave in ways that make a way out of the pandemic possible. In this chapter, it is argued that audience acceptance of appeals to experts is conditional in two ways. First, acceptance of expert opinions is conditional upon the degree to which appeals to expert opinions respect critical questions regarding the evaluation of these appeals. Second, acceptance of expert opinions is conditional upon the audience’s prior belief in the claims. It is argued that the most likely factor that has played a role in the lack of influence of experts is the weak consensus between experts when it comes to issues regarding the COVID-19 pandemic.
Hornikx, J. (2022). On the conditional acceptance of arguments from expert opinion. In Oswald, S., Lewinski, M., Greco, S., & Villata, S. (Eds.), The pandemic of argumentation (pp. 355-371). Springer. [link]
The persuasiveness of anecdotal evidence and statistical evidence has been investigated in a large number of studies, but the combination of anecdotal and statistical evidence has hardly received research attention. The present experimental study therefore investigated the persuasiveness of this combination. It also examined whether the quality of anecdotal evidence affects persuasiveness, and to what extent people comprehend the combination of anecdotal and statistical evidence. In an experiment, people read a realistic persuasive message that was relevant to them. Results showed that anecdotal evidence does not benefit from the inclusion of statistical evidence, nor from its intrinsic quality. The analysis of readers’ cognitive thoughts showed that only a minority of participants comprehended the relationship between anecdotal and statistical evidence.
Hornikx, J. (2018). Combining anecdotal and statistical evidence in real-life discourse: Comprehension and persuasion. Discourse Processes, 55 (3), 324-336.
The process of arbitration requires human reasoning and decision-making. Parties evaluate the evidence that is available to them and decide how to best present their case. Arbitrators aim to resolve a dispute by weighing the evidence and the legal arguments that are presented by each side. Researchers have underlined the importance of strong evidence in legal deliberations, but what exactly characterizes strong arguments? This chapter addresses this question as a first point. The characteristics of arbitrators, such as age, gender, and cultural background, may affect how arbitrators process arguments. Yet given the aim of arbitration to be an objective and neutral process, it is important to consider how such characteristics may impact the ultimate outcome of a case. This chapter examines the last of these characteristics, namely the role of culture in this decision-making process. More precisely, this chapter reviews the research evidence on how members of different cultures evaluate strong and weak arguments.
Hornikx, J. (2017). Cultural differences in the perceptions of strong and weak arguments. In T. Cole (ed.), The role of psychology in international arbitration (pp. 72-92). Alphen aan den Rijn: Wolters Kluwer. [link]
Studies on persuasive arguments have generally found that claims supported by high-quality evidence are better accepted than claims supported by low-quality evidence. However, an experiment by Hoeken and Hustinx (2007) demonstrated that this effect was only observed in short texts (a claim with evidence), but not in longer texts (where information unrelated to the evidence was added at the end of the text). The present experiment was conducted to examine whether this effect of text length could be explained by distraction (the additional text at the end distracts the reader) or by dilution (the additional text makes the fragment less diagnostic for claim evaluation). Participants (N = 629) read two texts with a claim supported by high-quality or low-quality (anecdotal, statistical, or expert) evidence. The text was presented in one of the three versions: (1) short, (2) long with additional information at the end, or (3) new in comparison to Hoeken and Hustinx (2007) – long with additional information at the start. The data found support for the distraction explanation. An effect of evidence quality on claim acceptance was observed in two conditions: in the short text, and in the longer text with additional information at the start. The effect of evidence quality was not found in the longer text with additional information at the end.
Hornikx, J. (2016). Evidence quality variations and claim acceptance: An experimental investigation of the role of distraction and dilution. Paglieri, F., Bonelli, L., & Felletti, S. (eds.), The psychology of argument: Cognitive approaches to argumentation and persuasion (pp. 211-222). London: College Publications. [paperbook]
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.
Hahn, U., & Hornikx, J. (2016). A normative framework for argument quality: Argumentation schemes with a Bayesian foundation. Synthese, 193 (6), 1833-1873. [link]
Over het algemeen raken mensen meer overtuigd door sterke dan door zwakke argumenten. In de empirische literatuur bestaan er echter inconsistente bevindingen voor het effect van argumentkwaliteit. In dit paper wordt onderzocht of de manipulatie van argumentkwaliteit een verklaring kan bieden voor deze tegenstrijdige bevindingen. Een analyse van dergelijke manipulaties in 32 uitgevoerde empirische onderzoeken leidt tot twee belangrijke inzichten. Ten eerste manipuleren onderzoekers voornamelijk pragmatische argumentatie, waarbij het standpunt over de wenselijkheid van de aanschaf van een product wordt ondersteund door te verwijzen naar de wenselijke gevolgen van het gebruik van dat product. Ten tweede blijkt de wijze van manipulatie sterk uiteen te lopen: bij de zwakke argumenten wordt soms naar minder wenselijke gevolgen verwezen, in andere gevallen naar neutrale gevolgen (waardoor er eigenlijk geen sprake is van een argument), en soms zelfs naar onwenselijke gevolgen (waardoor er geen sprake is van een zwak pro-argument maar van een tegenargument). Deze verschillende manieren waarop argumentkwaliteit in de 32 onderzochte studies gemanipuleerd werd, zouden een verklaring kunnen bieden voor de soms tegenstrijdige bevindingen in onderzoek naar argumentkwaliteit.
Weerman, A., Hoeken, H., & Hornikx, J. (2016). Een kritische analyse van de manipulatie van argumentkwaliteit in reclameonderzoek. In D. Van de Mieroop, L. Buysse, R. Coesemans, & P. Gillaerts (Red.), De macht van de taal: Taalbeheersingsonderzoek in Nederland en Vlaanderen (pp. 309-321). Leuven: Acco. [link]
Claims supported by high-quality evidence have been found to be more persuasive than claims supported by low-quality evidence. However, Hoeken and Hustinx (2007) showed that this effect was only observed in short texts (a claim with evidence), but not in longer texts (where information unrelated to the evidence was added at the end of the text). The current experiment was conducted to examine whether this effect of text length could be explained by distraction (the additional text at the end distracts the reader) or by dilution (the additional text makes the fragment less diagnostic for claim evaluation). Participants (N = 629) read two texts with high/low-quality evidence. The text was presented in three versions: short, long with additional information at the end, or – new in comparison to Hoeken and Hustinx (2007) – long with additional information at the start. The data found support for the distraction explanation: an effect of evidence quality on persuasiveness was observed in the short text, and in the longer text with additional information at the start, but not in the longer text with additional information at the end.
Hornikx, J. (2014). Het effect van evidentiekwaliteit op de beoordeling van standpunten: de rol van toegevoegde tekst. Tijdschrift voor Taalbeheersing, 36 (1), 107-125 [link].
The concept of argumentation schemes plays an important role in identifying real-life argumentation, and in assessing the quality of this argumentation by virtue of critical questions. Argumentation schemes have played a central role within argumentation theory since the second half of the last century. This special issue addresses two general topics related to argumentation schemes. In the first place, some papers tackle the question how argumentation schemes should be classified into a framework, and how they work together in argumentative discourse. In the second place, other papers address the question how language users employ criteria to evaluate argumentation.
Hornikx, J., & Jansen, H. (2014). Argumentatieschema’s [themanummer Tijdschrift voor Taalbeheersing]. Amsterdam: Amsterdam University [link].