published quarterly by the university of borås, sweden

vol. 25 no. 3, September, 2020

For or against Brexit? Justifying oppositional arguments in online discussion

Reijo Savolainen

Introduction. This investigation examines argumentation about political issues occurring in online discussion groups. A case study was made by concentrating on debates about Brexit - the prospective withdrawal of the United Kingdom from the European Union.
Method. Building on Toulmin’s model for argument patterns, it was examined how oppositional arguments about Brexit were grounded by drawing on facts and opinion-based evidence and how the evidence of information these types was justified. To this end, a sample of 40 discussion threads initiated before the 2016 Brexit referendum were downloaded from PoliticsForum - an online platform.
Analysis. The data consisting of 1563 messages were scrutinized by means of descriptive statistical analysis and qualitative content analysis. The focus was placed on the latter method by analysing the ways in which the discussants justified the rebuttal of opposing arguments.
Results. Oppositional arguments justifications were mainly based on the description of personal opinions and negative evaluation of opposing views. Analytic approaches to justification based on explanation and comparison were less popular. This preference is probably due to the lower cognitive effort required while simply describing the attributes of an entity or judging its positive or negative qualities by drawing on one’s beliefs and experiences.
Conclusions. Argumentation occurring in online platforms will form an increasingly important part of political struggles. On the other hand, online debates on controversial issues such as Brexit tend to be broad rather than deep.


Social media forums offer new opportunities to debate social and political issues. Recent evidence of the potential of social media was obtained from the United Kingdom’s Brexit referendum on EU membership in 2016. Official campaigns, politicians, and citizens engaged heavily in discussions on social media platforms to communicate Brexit-related information and arguments, gain attention, and influence voters. Arguably, the referendum about Brexit, a portmanteau of British and exit; the prospective withdrawal of the United Kingdom from the European Union - was the most significant political event in the UK in half a century (Hall et al., 2018, p. 21).

Although the main emphasis will be placed on the analysis of arguments presented in online debate, this study is also relevant for research on information sharing and use occurring in online forums. Since the 1980’s, there is a growing body of empirical research on this topic. The ways in which people share and use information in online forums have been examined in a variety of contexts ranging from political debate (Garramone et al., 1986), health-related issues (Zhang, 2016), consumer awareness (Savolainen, 2015b) and hobbies (Lee, 2009).

The present study enriches the repertoire of studies of this kind by focusing on political debate among citizens. The present investigation contributes to research on the use of social media platforms by examining Brexit debates occurring in an online discussion group before the 2016 referendum. The study was inspired by the idea that argumentation occurring in online platforms will form an increasingly important part of political struggles. In the case of the Brexit referendum, such platforms offered people open venues to defend their arguments and possibly appeal to voters considering whether the UK should remain in the EU or leave it. To examine this issue, an empirical study was made to find out how the participants of online discussion bolstered their arguments informationally by drawing on facts and personal opinion. The research topic is unique because, to my knowledge, there are no previous studies on the Brexit debates occurring in online discussion groups. Drawing on Toulmin’s (2003) model for argument patterns, the present study concentrates on the nature of oppositional argumentation. It emphasizes the role of rebuttals questioning the evidence presented by the discussants. As Brexit is a controversial issue, opposing arguments are common in online debates. Therefore, successful argumentation depends on how the participants are able to defend their arguments. To examine this issue in greater depth, this study seeks answer to the following question: how are oppositional arguments about Brexit justified in online discussion by drawing on facts and opinion-based evidence?

The rest of the article is organized as follows. First, to provide background, the nature of argumentation occurring in online forums is characterised and the main issues of Brexit are briefly described, followed by the specification of the conceptual framework and the empirical research setting. Thereafter, the empirical findings are reported; the final sections draw conclusions from their significance.


Argumentation in online forums

Argumentation can be generally defined as a discursive process involving at least two individuals engaged in dialogue, each contending differing positions and trying to persuade each other (Tindale, 2004, pp. 2-3). Zarefsky (2008, p. 632) characterized argumentation as the ‘practice of justifying claims under conditions of uncertainty’. Therefore, argumentation establishes not what is objectively true, but what a person should consider to be true. It involves proffering and testing claims against the scrutiny of others. The claims that withstand critical scrutiny, though they cannot be verified, can be taken as true and acted upon with a high degree of confidence.

Since the 1990s, online discussion groups have provided venues for argumentation about diverse topics ranging from health issues to daily politics (Himelboim, 2008). Different from argumentation occurring in face-to-face conversation between two speech partners, online debates are characterized by multivocal and sometimes chaotic exchanges among the participants (Marcoccia, 2004). In online discussion groups, argumentation is based on the messages submitted by the participants. The messages are contained in threads, where they appear one after another so that the first post starts the thread focusing on a topic. A thread can contain any number of posts, including multiple posts from the same contributors, even if they are one after the other.

Politics occupies a prominent place among the topics debated in online discussion forums. Himelboim (2008) characterised political discussion groups as opinion-based conversation forums where one participant’s opinion is unlikely to be more or less valuable than another’s. According to Lewinski (2010, p. 90; p. 103), political discussions occurring in online discussion groups are informal and bottom-up initiatives hosted by politically engaged internet users. In such forums, opinions are publicly expressed, challenged, defended and criticized. As online discussions are a specimen of informal public deliberations, they are not necessarily concluded by binding decisions reached at the end of the process of exchange of arguments. Moreover, the lowered sense of social presence experienced online may encourage expression of dissenting views. Therefore, online forums can allow people to reinforce their predilections, based on their interactions with agreeable associates. In this case, online discussion groups may serve as echo chambers where like‐minded people are exposed to one‐sided arguments, which can further reinforce their initial predilections (Wojcieszak and Mutz, 2009, p. 42).


The UK joined the European Communities (EC) in 1973, with membership confirmed by a referendum in 1975. From the 1990s, the withdrawal from the EC has mainly been advocated by the United Kingdom’s Independence Party (UKIP) and an increasing number of Eurosceptic members of the Conservative Party. Under pressure from many of his MPs and from the rise of UKIP, Conservative Prime Minister David Cameron announced in 2013 that a Conservative government would hold an in-out referendum on EU membership, if elected in 2015 (Mölder, 2018). The Conservative Party won the general election, and Cameron kept his promise by announcing that the referendum would take place 23 June 2016.

The referendum was preceded by a number of campaigns defending the pros and cons of leaving or remaining a member of the EU. Kramer (2016) provides a useful summary of the main arguments presented by the Leavers and Remainers (see Table 1).

Table 1: Brexit: pros and cons (Kramer, 2016, 14-15)
FactorsArguments for Britain leaving the European Union (Leavers)Arguments against Britain leaving the EU (Remainers)
The costs of EU membershipBritain pays 13 billion pounds (annually).Britain receives back 4.5 billion pounds.
TradeBritain could have access to the single market without being bound by EU law.
British Gross Domestic Product (GDP) might fall only slightly if it left the EU.
Britain can maintain its own currency.
Britain is one of the world’s largest economies and should negotiate a more favourable relationship with the EU.
Over 50% of British exports go to the EU.
No tariffs are imposed on trade between member countries.
Britain benefits from EU trade deals with other countries.
Britain may not get a favourable trade agreement with the EU.
Britain’s GDP will fall.
InvestmentFree of EU rules, Britain could return to the major financial hub in the world. International banks might leave Britain and set up their headquarters in the EU.
Britain’s car industry would be less competitive if it had to pay tariffs to sell in the EU.
SovereigntyBritain will not be subject to many of the rules of the various bodies in the EU.Britain could renegotiate some the rules applied by the EU.
ImmigrationBritons can restrict the number of immigrants from EU member countries, especially from Eastern and Southern Europe.Many Britons have benefited from moving to EU countries for work or retirement.
Britain will lose many of its links with Europe.

As Table 1 suggests, the arguments against Brexit emphasised the significance of economic issues. It was predicted that Brexit would reduce UK's real per-capita income in the medium and long-term (Sampson, 2017). Moreover, it was speculated that British companies would become less competitive in global markets. Brexit would also reduce immigration from European Economic Area countries to the UK, thus posing challenges for UK higher education and academic research in particular. Overall, many of the arguments supporting the Remain option emphasised the potential of the EU co-operation and warned about the economic risks of the Brexit. The Leave side drew on opposite arguments. It was believed that in terms of economy, the benefits from Brexit will outweigh the costs of membership. The UK could be brought back as a self-determining democratic state, free from EU regulations. Brexit would also enable curbing immigration to the UK.

In the referendum, 51.9% voted in favour of leaving the EU, and 48.1% voted in favour of remaining a member of the EU. The choice made by voters caused a ‘political earthquake’, giving rise to the Brexit process (Wincott et al., 2017, pp. 429-430). Researchers have provided different explanations for the result of the referendum. For example, Hopkin (2017) contends that the vote for Brexit was not an isolated event, but part of a wave of populist, anti-elite revolts: a new ‘anti-system’ politics Western democracies are experiencing. Failed policy consensus, a rise in inequality and a decline in the representativeness of political elites, rather than a resurgence of intolerance or xenophobia, were the principal causes of the Brexit vote.

The role of social media in referendum debates

The Brexit vote was preceded by the 2014 Scottish interdependence referendum, a political process affecting the Brexit debates. Baxter and Marcella (2017) interviewed fifty-four participants as they searched for and used information on the websites and social media sites of the Scottish referendum campaign groups. An attempt was made to identify how the participants value facts, what they perceive as authoritative voices, and how they assess the capacity to compare campaign messages by focusing on infographics and concise, direct information. The findings indicate that the participants preferred expert messages; however, they were uncertain about their personal capacity to evaluate information they will use to make decisions. Most of the interviewees who talked about social media as a source of information about the referendum reported positive use: ‘makes it easy to engage in conversations ... it does make for better engagement’ (Baxter and Marcella, 2017, p. 543). On the other hand, respondents also expressed criticism towards social media generally, citing the ‘nastiness’ of social media discourse, as well as its superficiality.

The ways in which the issues of Brexit have been debated in social media have been examined by communication scientists in particular. Most of these studies concentrate on the use of Twitter and Facebook, while so far there are no investigations examining the role of online discussion groups. Bastos and Mercea (2018) mapped the political value space of users tweeting the Brexit referendum on to parliamentary constituencies. The study revealed a significant incidence of nationalist sentiments and economic views expressed on Twitter. Although nationalism appeared to have been a critical marker of the Brexit value space, populist messages, however, were decidedly of lesser importance compared with the sheer volume of tweets discussing the economic consequences and opportunities of Britain leaving the EU.

To map the social dynamics of the Brexit debate on Facebook, Del Vicario and associates (2017) performed a massive analysis on more than one million users interacting with Brexit related posts. The findings revealed the existence of two distinct communities of news outlets. These communities are polarised and represent different echo chambers where the interaction with like-minded people, either for or against Brexit, tend to reinforce polarization. Lilleker and Bonacci (2017) examined Facebook pages of four organizations: the two official Campaigns, Leave EU and Stronger In, as well as two unofficial but reasonably large competitors, Let’s Stay in Europe (Let’s Stay In) and Vote Leave. The findings indicate that the Leave campaigners were proactive posters, creating more engaging content and, in turn, gaining an advantage in terms of visibility online. Leave supporters were also more prone to act as cheerleaders for the campaign applauding attacks on Remain leaders. Remain subscribers similarly endorsed negative messages but were keener to debate the detail behind slogans and critique the official campaign strategy and messaging. More recently, Bossetta et al. (2018) explored political participation on Facebook during a period of eighteen months surrounding the Brexit referendum. The study focused on the commenting activity of nearly two million Facebook users engaging with political news from British media or with the posts of referendum campaigns. The findings suggest a positive correlation between political interest and online participation on Facebook. On the other hand, the majority of users (70%) contributed only one comment to the campaigns.

Conceptual framework

As this study is mainly interested in the nature of oppositional dialogue, Toulmin’s (2003) model for argument patterns was chosen as point of departure. The model dates back to the 1950s when Toulmin developed a schema for the rational assessment of practical arguments presented in everyday dialogues. His model has been used to examine argumentation in diverse contexts, including online learning environments (Clark et al., 2007) and online discussion occurring in Question and Answers sites (Savolainen, 2012).

Toulmin (2003, pp. 87-100) specified six major elements of argumentation; the illustrating examples of the Brexit issues draw on the empirical data of the present study.

Ideally, argumentation moves from the data (evidence) to the claim (conclusion) based on the reasoning provided by the warrant. A backing and qualifier may reinforce the warrant, while a rebuttal shows objections to the claim. Overall, the strength of Toulmin's model resides in its ability to evaluate arguments in an analytical manner.

On the other hand, researchers have faced problems while applying Toulmin’s model in empirical research (Clark et al., 2007). It is often difficult to make objective distinctions between the elements of data, warrant, and backing when analysing argumentation, resulting in poor reliability. To avoid this problem, Erduran et al., 2005) collapsed the elements of data, warrant, and backing into a single category of grounds. The present study follows this methodological idea by employing the composite category of grounds which also incorporates the element of qualifier. Further, drawing on the ideas of Jimenez-Aleixandre et al. (2000) and Clark and Sampson (2007), Toulmin’s model was elaborated by adding two new elements, that is, counterclaim and support. This is because the participants of an argumentative discussion may not only rebut claims. They can also present counterclaims indicating disagreement with a claim by contending, for example, that ‘Brexit will not decrease the average annual household income’. The participants may also indicate support by agreeing with a claim, counterclaim, or rebuttal presented in the discussion. In addition, the present study made use of two additional categories, that is, question and comment. The former refers to a specifying request presented by a participant of discussion, for example, ‘what exactly did you mean by average annual household income?’ The latter refers to a non-evaluative statement offering an answer to a question, for example, ‘I meant the average income calculated by the Office for National Statistics’.

The construct of grounds was specified further by drawing on the study conducted by Savolainen (2012). Grounds stand for sources of evidence bolstering claims, counterclaims, rebuttals, comments and indications of support. Two main types of grounds (sources of evidence) were identified. First, the elements of argumentation may be bolstered by drawing on facts. In general, a, fact can be understood as a piece of information presented as having objective reality; in this regard, a fact is something that can be checked and backed up with evidence (for example, ‘in 2014-2015, according to the Office of National Statistics, mean annual household income in the UK was ₤31,440’). Secondly, the elements of argumentation can be bolstered by drawing on personal opinion. It indicates an individual’s view on an issue at hand, based on his or beliefs, values and experiences. In contrast to a fact, a personal opinion is not based on evidence whose truthfulness of untruthfulness can be checked (for example, ‘Brexit will ruin the UK for decades’). Finally, the conceptual framework was elaborated by specifying the ways in which personal opinions and facts can be justified as sources of evidence. To this end, the present investigation drew on the framework of cognitive mechanisms constitutive of information use (Zhang et al., 2008). Mechanisms of this kind include, for example, comparison, explanation and generalization that people employ while interpreting the relevance of information available in diverse sources. Savolainen (2009) elaborated these categories in a study focusing on how prospective homebuyers assess the relevance of information needed in the decision-making. Due to their generic nature, such mechanisms also appeared to be relevant as ways used to justify personal opinion or facts about the Brexit issues. As a result, the following categories were used to indicate the ways in which the grounds were justified in argumentation about the Brexit.

Building on the categories defined above, the conceptual framework of the present study is presented in Figure 1.

Figure 1: Conceptual framework

Figure 1: The conceptual framework

Figure 1 suggests that debates occurring in online discussion groups are constituted by six major elements of argumentation: claim, question, comment, support, counterclaim and rebuttal. A discussion thread can incorporate one or fewer “chains” of argumentation constituted by these elements. A claim initiating argumentation about a topic is usually presented in the initial message of the discussion thread. Sometimes, however, the claim is presented in a later message because the initial post may simply introduce the topic or present a general-level question without a specific claim (for example, ‘Not really fully into politics, but I have been reading about the whole EU do we leave or stay, what really is for the best and why?’). The chain of argumentation begins when one of the participants presents a claim about an issue, potentially giving rise to specifying questions and comments from other participants. Depending on the nature of the claim, subsequent messages can also incorporate other elements of argumentation such as indication of support, counterclaim and rebuttal (or a combination of these elements). The present study concentrates on the examination of the relationships between claims and rebuttals constitutive of oppositional argumentation. The main emphasis will be laid on the ways in which rebutting arguments are grounded by personal opinion or facts and how such grounds are justified. However, to put the oppositional argumentation in a broader context, a descriptive quantitative analysis will be made to find out how frequently diverse elements of argumentation appear in Brexit debates.

Research questions

Drawing on the above framework, the study addresses the following research questions:

The answer to the first research questions provides an indicative (rough) quantitative overview of the nature of argumentation about Brexit issues, while the second research question probes into the nature of evidence used to bolster the rebuttals. Finally, response to the third research question specifies how personal opinions and facts are justified as evidence in Brexit debates.

To sharpen the focus of the study, a few limitations were necessary. First, no attention is devoted to the relationships between counterclaims and rebuttals in the qualitative analysis of this study does not examine the nature of affective elements of argumentation. Given the space restrictions alone, it is evident that the above issues would have required a separate study.

Empirical data and analysis

The empirical data were gathered from PoliticsForum - an established online platform providing room for debate about UK politics and current affairs. The data were collected in May 2018 by downloading a sample of the forty most recent discussion threads initiated before the Brexit referendum. This sample appeared to be sufficient for the needs of the study because it enabled an indicative quantitative picture of the elements of argumentation and allowed a detailed qualitative analysis of the oppositional argumentation. Threads containing fewer than ten messages were excluded from the sample because the preliminary reading of the posts revealed that short threads fail to incorporate a sufficient number of elements constitutive of full-fledged oppositional argumentation. Moreover, threads with more than 100 messages were excluded because it appeared that long threads would not provide added value to the empirical analysis of the ways in which oppositional arguments were justified. In long threads such as these, the level of discussion was often lowered because the participants repeated their arguments or detracted from the original topic.

The sample of forty threads contained altogether 1563 messages posted within the period of 14 April -23 June 2016. During this period, there were altogether 107 Brexit-related discussion threads in PoliticsForum; thus, the sample contained 37.4% of the threads. In the sample, the number of messages per thread varied from 10 to 98. Altogether seventy-five individual participants contributed to the above threads. There was a handful of really active participants; the most active of them posted no fewer than 143 messages. On the other hand, 39% of the participants were occasional contributors submitting one or two messages.

In coding the data, text portions, that is, sentences or text paragraphs focusing on a Brexit-related issue such as the cost of EU membership was used as the coding unit. The relevant parts of the messages were coded by making use of the categories specified in Figure 1 above. First, a claim presented by the thread initiator was coded. If he or she presented multiple claims on diverse issues, only the claim presented first was coded; other claims were simply ignored. In most threads, several claims were presented by diverse participants. In these cases, each additional claim on a different topic initiated a sub-thread potentially incorporating other elements of argumentation. Secondly, a claim was examined to determine whether it was grounded by personal opinion or fact (or both) and whether the ground was justified in some way, for example, by drawing on explanation. If neither personal opinion nor fact was explicitly offered as an evidence, the ground was coded as empty. The coding was continued by examining the subsequent messages to identify whether they incorporate specifying questions, comments, indications of support, counterclaims and rebuttals dealing with the first claim coded for the analysis. A code was assigned to an element (for example, rebuttal) when it occurred for the first time within a message; other instances of the same element, for example, restatement of a rebuttal within the same message, were simply ignored.

To strengthen the validity of the coding, I checked the initial coding iteratively. Because the study does not aim at statistically representative generalization of online forums debating political issues, the requirement of the consensus on coding decisions based on inter-rater reliability can be compromised without endangering the reliability of the exploratory study. According to Miles and Huberman (1994, p. 64), check‐coding the same data is useful for the lone researcher, provided that code–recode consistencies are at least 90%. Following this idea, check‐coding was repeated, and the initial coding was carefully refined. Check‐coding revealed a few boundary cases regarding the categories of counterclaim and rebuttal. These cases were resolved by scrutinizing the content of the message in the context of the thread or sub-thread. The refining of the coding was continued until there were no anomalies.

To answer the first research question dealing with the quantitative distribution of the elements of argumentation, the data were scrutinized by means of descriptive statistics. More importantly, to answer research questions 2 and 3 focusing on the grounding and justification of rebuttals, qualitative content analysis was conducted. More specifically, the constant comparative method (Lincoln and Guba, 1985) was used to capture the variety of articulations constitutive of rebutting arguments, as well as the ways in which personal opinions and facts were presented as sources of evidence. However, the focus was placed on scrutiny of the ways in which the evidence for rebuttals is justified in the oppositional argumentation.

Because the contributors to the PoliticsForum are expected to be aware of the fact that their messages will become publicly available on this platform, no attempts were made to contact the participants to obtain permission for the use of their messages in the present study. Asking permission would have been difficult in practice because many of the participants appeared to be occasional contributors: it is unlikely that they are motivated in answering for requests such as these. However, when using the illustrative extracts taken from the messages, the anonymity of the participants is carefully protected. Their nicknames are replaced by neutral identifiers such as Participant 1 and Participant 2, while an individual thread is referred to as Thread 24, for example. Given the high number of discussion threads focusing on the issues of Brexit, it is unlikely that such extracts could be associated with an individual contributor.


The elements of argumentation: a quantitative overview

In the forty threads, altogether 366 claims, that is, on average nine claims per thread were presented. The number of claims per thread varied between one and thirty-two Table 2 provides a quantitative overview of the elements constitutive of Brexit discussions occurring in the PoliticsForum. The percentage distribution was calculated from the frequency of codes (n = 2056) assigned to elements of argumentation.

Table 2: Percentage distribution of the elements of argumentation about Brexit issues (n=2056)
Claim 17.8
Counterclaim 7.7
Total 100.0

Comment was the most frequent element of argumentation, followed by claims and questions. Rebuttals occupied 12.6% of the codes assigned to the messages, while the share of counterclaims remained somewhat lower, that is, 7.7.%. Indications of support were seldom presented.

In most cases, the elements of argumentation were grounded by drawing on personal opinion; no less than 93.7% of the codes assigned to the messages belonged to this category. Thus, the share of facts as source of evidence remained fairly low, that is, 6.3%. This suggests that the Brexit debates occurring in the PoliticsForum are dominated by the description of personal opinions while fact-based evidence is presented quite seldom. Table 3 specifies how the participants justified the grounds. The percentage distribution was calculated from the frequency of codes (n = 2117) assigned to the ways of justification.

Table 3: Percentage distribution of the ways of justifying the grounds (n=2117)
Negative evaluation 15.5
Explanation 8.4
Reference to external source of information6.0
Comparison by difference 3.8
Positive evaluation 2.5
Generalization 0.4
Comparison by similarity 0.3
Total 100.0

Almost in two cases out of three, the grounds were simply justified by describing the sources of evidence, that is, depicting one’s opinion about an issue or offering a statistical fact. The shares of other ways of justification were much smaller. However, negative evaluations (15.5%) were quite frequent, thus suggesting that Brexit discussions are often characterized by unfavourable assessments. The participants also drew on explanations (8.4%) and justified the grounds by providing references to external sources of information (6%). The role of other ways of justification remained marginal. Nevertheless, comparison by difference was used in a few cases, as well as providing positive evaluation of an issue. Generalizations (0.3%) were seldom presented, similar to comparisons by similarity (0.3%).

Justifying the grounds for rebuttals

The quantitative analysis revealed that personal opinions were far more popular than facts as sources of evidence for rebuttals; personal opinions comprised 86.8% of the codes assigned to grounds while the share of facts was 13.2%, respectively. The above findings were elaborated by means of qualitative analysis by scrutinizing the ways in which the grounds for rebuttals were justified in oppositional argumentation. Although counterclaims are integral elements of oppositional argumentation, they are not discussed in greater detail because they are less interesting from the perspective of justifying the grounds. Counterclaim simply indicates a disagreement with a claim, for example, that Brexit will destroy the UK economy, while rebuttals focus on how claims can be challenged by contending that they are based on insufficient evidence or faulty reasoning. Due to space restrictions, only the most frequent ways of justifying the grounds for rebuttals will be examined qualitatively: description, negative evaluation, explanation and comparison by difference. The role of references to external sources of information will be reviewed while analysing the nature of multiple justifications because such references were not employed independently from other ways of justification. The findings are presented by making use of extracts taken from the threads containing oppositional argumentation. To avoid overly long examples, the extracts present only one rebuttal per way of justification.


The most frequent way used in the justification of grounds for rebuttals was description. No less than 34.9% of the justifications drew on the description of personal opinion or fact used as a source of evidence. Description is a neutral (non-evaluative) way of justification in that it just depicts the content of the evidence. We may characterize this approach by analysing a couple of examples typical to the ways of justification. Extract 1 illustrates oppositional argumentation in cases in which claims were rebutted by drawing on factual evidence. One of the threads debated whether the UK Parliament should have more power to decide the level of value-added tax (VAT).

Extract 1 (Thread 2)
Message 1 (Participant 1)

We are not allowed to decide for ourselves a value-added tax on women's sanitary products, even though all of the major and minor political parties in this country don't want any VAT tax on these products. The EU held a meeting of all 28 EU commissioners and decided that we must put this tax on.

Message 2 (Participant 2)

Mate, seriously when you are in a hole, stop digging. It is a matter of fact that there are collective VAT rules across the EU. The EU's member governments agreed to change the VAT rules on UK suggestion. So, your accusations of lack of influence, etc. simply don't stack up.

The factual ground for the rebuttal is justified simply by describing the objective states of affairs, that is, the fact that there are collective VAT rules across the EU and that they are based on the decision made by EU member governments. The evidence is factual because the existence of collective VAT rules and the decisions made by the EU member governments can be checked by consulting official documents such as the minutes of government meetings. Importantly, the rebuttal incorporates a critical view on the logic used by the thread initiator: ‘when you are in a hole, stop digging’. Moreover, the faulty logic of Participant 1 is criticised by erroneous ‘accusations of lack of influence from the side of the UK government’, although in fact, the VAT rules were changed on the suggestion of UK government.

Another example illustrates the case in which a rebuttal drawing on personal opinion is justified by describing one’s view on anticipated budget cuts caused by Brexit. The debate was ignited by an internet source (BBC News) where George Osborne, Chancellor of the Exchequer warned about the risks of Brexit.

Extract 2 (Thread 30)
Message 1 (Participant 1)

I'm surprised there is no comment on this just yet, but even by George's standards this is sneaky and low: http://www.bbc.co.uk/news/uk-politics-e ... m-36534192

This fuels my belief that the so-called split along EU lines in the Conservative party has been pre-designed and executed. It’s starting to look to me like one giant stitch up, stay in the EU and they claim pass off the blame for unpopular decisions onto the EU, leave and pass on the blame to Brexiters and their supporters.

Message 2 (Participant 2)

As far as I'm aware, there is currently no evidence to support your argument of what is currently happening. There is some evidence to show there is currently a global turndown in growth, but that can hardly all be down to Brexit worries.

The rebuttal voiced by Participant 2 questions the claim by contending that it lacks sufficient evidence of the strategy developed by the Conservative Party. This opinion is justified by doubting that a global economic turndown cannot be explained by Brexit worries alone. Interestingly, Participant 2 made no attempt to strengthen the rebuttal by commenting on Osborne’s statement published by BBC News. This suggests that justifications merely describing one’s opinion about an issue tend to remain at a general level.

Negative evaluation

Rebuttals were justified equally often by drawing on negative evaluation; 34.5% of the codes assigned to the ways of justification for rebuttal belonged to this category. Interestingly, there were no cases in which factual evidence was justified in this way. Negative evaluation was mainly used to put the presenters of claims in a doubtful light so that arguers would not be taken seriously. Particularly topics dealing with immigration attracted rebuttals justified by negative evaluation.

Extract 3 (Thread 6)
Message 1 (Participant 1)

If we want to know the real numbers of those entering this country legally and illegally, the government and the BBC should ask Nigel Farage. After all, he said a few years ago that we should expect 50,000 immigrants from Portugal and Romania to arrive in the UK per year.

Message 2 (Participant 2)

Congratulations! This is the millionth irrelevant thread about the EU. You have won a Nigel Farage badge with rolling eyes, a lifetime subscription to the Daily Mail, and a framed picture of Boris Johnson.

Participant 2 rebuts the claim by ridiculing the thread initiator. Thereby, the estimation of the number of incoming immigrants is put in a dubious light. Typically, rebuttals justified in this way tend to draw on an ad hominem approach. It is a rhetorical strategy persuading people to think that the claims presented by a person should not be taken seriously due to his or her biased opinions. More generally, it appeared that particularly claims drawing on the views of Nigel Farage and David Cameron often gave rise to rebuttals justified by negative evaluation, thus reflecting the adversarial nature of the Brexit debates.


Rebuttals were also justified by drawing on explanation; 19.9% of the codes assigned to ways of justification indicated the use of this approach. Explanation draws on “if - then” reasoning by identifying a cause and consequence(s) of decisions and actions. Similar to negative evaluation, explanation was mainly used while drawing on personal opinion as evidence. The following example dealing with the role of the EU as a provider of economic security illustrates how explanation was employed in the justification of opinion-based rebuttals.

Extract 4 (Thread 17)
Message 1 (Participant 1)

The main plank of the remain argument is the economic security the EU provides. Thus, if we leave the EU, this, as they say, could have negative economic consequences for the UK, affecting jobs and prosperity. Which exists in and outside the EU thus, any event on the global stage is a risk to jobs and prosperity of any country. The EU did not secure jobs and prosperity because everyone is so tightly interconnected.

Message 2 (Participant 2)

I’m afraid your logic fails. The fact that we are interconnected and membership or otherwise of the EU cannot protect us from world events does not mean that there would be no economic consequences of leaving the EU. There is no logic to that connection at all. Nearly all economists, business leaders, financial organisations, etc. agree that the UK economy is likely to be significantly affected by leaving the EU - both in the short term and the long term. It is an illogical view to pretend that they do not exist.

The rebuttal is based on a personal opinion contending that the reasoning about the negative economic consequences of Brexit is poorly constructed. Participant 2 refers several times to the flawed logic of the thread initiator while justifying the rebuttal: ‘I’m afraid your logic fails‘; ‘there is no logic to that connection at all’; and ‘It is an illogical view’. The failures of reasoning are explained by referring to problematic assumptions such as that the UK would be sheltered from economic shocks outside the EU. Thereafter, the consequences of Brexit are explained by speculating how the UK economy would still be affected by uncertainty. As a way of justification, explanation differs from negative evaluation in that the main attention is directed to the validity of reasoning, not the values held by the opponent. Thus, in comparison, explanation exemplifies a more analytic way of justifying the grounds.

Comparison by difference

Finally, rebuttals were justified by drawing on comparison by difference. It was used relatively seldom because only 3.8% of the codes assigned to the ways of justification belong to this category. Therefore, only one example will be taken to illustrate how the participants made use of comparison by difference. In Extract 5, they speculated the consequences of Brexit.

Extract 5 (Thread 21)
Message 1 (Participant 1)

Once we have voted to leave, how isolated will we be? I believe there will be a contagious effect in other 'EU' countries with demands for their own referenda.

Message 2 (Participant 2)

Brexit will have the reverse effect. Others in EU countries that may be considering pushing for in/ out referendums will see the economic effects of a vote to leave and decide that they do not want what the UK has imposed upon itself through sleepwalking into leaving. Unlike the British, other countries will know exactly what leaving means economically after the event. No "scaremongering" from the experts needed for them, they will see for themselves the after effects.

The rebuttal voiced by Participant 2 draws on his or her critical opinion about the negative consequences of Brexit. Participant 2 then rebuts the assumption about the ‘contagious effect‘ in other EU countries by making use of comparison by difference. It suggests that other EU countries could not be subject to ‘scaremongering‘ campaigns and would thus choose an opposite way, based on the negative experiences obtained from post-Brexit UK. However, comparisons of this kind may be speculative because in spring 2016 there were no experiences of “exit” referendums organized in EU countries.

The above extract suggests that the grounds for rebuttal justified by a single way may remain unspecific. However, there were cases in which rebuttals were justified in multiple ways. The final example is taken from a thread speculating the pros and cons of voting for remain. The claim presented in message 1 draws on a video clip titled as ‘Dishonesty on an industrial scale‘. In the video, an EU law expert, University of Liverpool Law School’s Professor Michael Dougan analysed the referendum debate.

Extract 6 (Thread 38)
Message 1 (Participant 1)

I was in the leave camp for a good while over time. I am now thinking I might vote remain. This video in this article gave facts and made a lot of difference https://news.liverpool.ac.uk/2016/06/16/watch-dishonesty-industrial-scale-eu-law-expert-analyses-referendum-debate/

Message 2 (Participant 2)

I listened to part of the clip, but it got fairly ridiculous, so I gave up. For a start he accuses the leave campaign of lying "on an industrial scale". The only "lie" that I can think of is the statement on their battle bus that "We send £350 million a week to the EU". This is not true because we deduct the "Fontainebleu abatement" so, it's more like £270 million. That's NOT an industrial scale lie. The industrial scale lies are from the Remain campaign. Nearly all their claims are based on predictions and nearly all their predictions are based on the assumption that not only do we fail to negotiate any trade agreements with the EU, but that we also fail to negotiate any agreements with non-EU countries - which is obviously unrealistic. Some of the predictions are also based on faulty calculations, like, for example, the £4,300 pa loss of household income, where they have conflated GDP and income - and also failed to account for rises in population due to uncontrolled immigration. He then claims that our Parliamentary law is "supreme". This is bollocks. The Maastricht Treaty places the ECJ above nation's parliaments. This is a matter of fact. The guy's a liar.

The rebuttal is grounded on both personal opinion and facts. Participant 2 has a negative view on the credibility of the video clip which is labelled as ‘ridiculous‘. The EU law expert criticizing Brexit is evaluated very negatively by concluding that ‘the guy’s a liar‘. Participant 2 also draws on facts while rebutting the claim. For example, the factual claim about the £4,300 annual loss of household income is questioned because the above sum is based on a faulty calculation conflating gross domestic product and income. The justification is based on the description of the faulty calculation method. Participant 2 also rebuts the factual claim that the UK parliamentary law is supreme because the Maastricht Treaty places the European Court of Justice (ECJ) above nation’s parliaments. Overall, the above extract suggests that multiple ways of justifying the grounds may enable a more detailed argumentation, thus increasing the possibility that the rebuttal would be found credible among the participants of online discussion.


Building on Toulmin’s (2003) model for argument patterns, the present study contributed to research on argumentation occurring in online discussion groups. The quantitative analysis revealed that comment was the most frequent element of argumentation in the Brexit discussions, followed by claims and specifying questions. The share of counterclaims and rebuttals constitutive of oppositional argumentation formed altogether 20.3% of the codes assigned to the messages. This suggests that despite an adversarial topic, explicitly oppositional argumentation forms only a part of the political discussions occurring in online forums. It also appeared that the majority of elements of oppositional argumentation were grounded by expressing personal opinions. The quantitative analysis revealed that personal opinions were far more popular than facts as sources of evidence for rebuttals; personal opinions comprised 86.8% of the codes assigned to grounds while the share of facts was 13.2%, respectively. The most frequent way of justifying the grounds was description; no less than 63% of the codes assigned to the messages represent this category. Moreover, negative evaluations were quite common while justifying rebuttals in particular. The participants also justified, although less frequently, the grounds by drawing on explanation, comparison by difference and references to external sources of information.

Qualitative content analysis focusing on the justification of rebuttals elaborated the picture of oppositional argumentation. The preference for description as a way of justifying opinion-based or factual rebuttals suggests that Brexit debates occurring in online forums are broad rather than deep. The popularity of negative evaluation as a way of justification is mainly due to the controversial discussion topic. Opposing views are labelled as biased, thus suggesting that their presenters should not be taken seriously. Compared to description and negative evaluation, explanation exemplifies a more analytical way of justifying the grounds. However, explanation was rarely used in the justification of rebuttals although Brexit issues provide a wealth of opportunities for if - then reasoning. However, the potential of analytical approaches such as these was seldom used in the argumentation. It also appeared that the use of multiple ways of bolstering the grounds by combining description, negative evaluation, explanation, comparison by difference and references to external sources of information enable more effective ways to justify the rebuttals. However, multiple approaches were rarely used in oppositional argumentation.

Overall, the findings suggest people prefer descriptive and evaluative rather than comparative and explanatory approaches while justifying the evidence for rebuttals in online discussions. This preference is probably due to the lower cognitive effort required while simply describing the attributes of an entity or judging its positive or negative qualities by drawing on one’s beliefs and experiences. From this perspective, the justification based on explanation and comparison are less popular because they require more cognitive effort.

The evaluation of the novelty value of the research results is rendered difficult due to the paucity of similar studies. However, there are a few prior investigations offering possibilities for the comparison of the findings. Savolainen (2012) employed Toulmin’s (2003) model in the examination of argument patterns used in the debates on global warming at a Yahoo Answers Q&A site. Similar to the Brexit debates, the oppositional arguments about global warming were mainly based on the expression of personal opinions. On the other hand, self‐claimed expertise or merely drawing on one's personal beliefs may elicit more doubt than credibility, thus giving rise to additional counterclaims or rebuttals. However, online debates are not necessarily concluded by binding decisions reached at the end of the process of exchange of arguments and criticisms (Lewinski, 2010). No single person can be seen as an agent able to carry the burden of proof successfully from the confrontation to the point of coming to a reasonable conclusion, and thus to the point at which a difference of opinion is resolved.

Another possibility for the comparison of findings is provided by Savolainen’s (2015a) study on how people offer informational support for travel planning in online forums. It appeared that 64% of the messages providing informational support drew on personal opinions. Discussions about controversial topics such as Brexit seem to be even more strongly based by personal opinions because the present study revealed that share of grounds of this type was 93.7%. The comparison of the ways of justifying the grounds revealed that negative evaluations are more common in political debates: in the context of travel planning, their share was marginal. In contrast, positive evaluations were much more common while providing support for travel planning. In the context of travel planning as well as Brexit, the role of analytic ways of justification remained quite marginal. For example, comparison by differentiation appeared to be quite rare since 7% of all mentions of grounds used to support travel planning drew on comparison by differentiation, while share of this category in the context of Brexit was 3.8%. Finally, similar to Savolainen’s (2015a) investigation, the role of references to external sources of information remained marginal. In Brexit debates, external sources most often referred to by the participants were newspaper articles and television programmes.


The main contribution of the present study is the empirical specification of the ways in which rebuttals as core elements of oppositional argumentation are justified in online discussion about controversial issues. The findings highlight the discussants’ preference for opinion-based and descriptive justifications of arguments while the analytic approaches to justification are less popular. This is probably due to that the latter ways of justification require more cognitive effort.

Because the present study examined argumentation focused on a politically-sensitive topic occurring in as single online platform, caution should be taken in generalising these results to other online discussion fora or social media sites. Moreover, due to space reasons, the qualitative analysis was confined to the scrutiny of one rebuttal per way of justification although online debates may incorporate a series of rebuttals. There is a need to elaborate these issues in future studies on online argumentation. Moreover, the study of online argumentation may be elaborated by making use of alternative research approaches. This is reasonable because one of the limitations of Toulmin's (2003) model is that it takes a somewhat schematic approach to the specification of the elements of argument, as well as their relationships. For example, Toulmin's model does not draw attention to the complexities of rhetorical situations in which argumentation takes places (Crosswhite, 2008). To examine these issues, the ideas of rhetoric could be used in the analysis of the argumentation process (Tindale, 2004). Intriguing questions include, for example, what kind of rhetorical devices and strategies are used in the defence of counterclaims and rebuttals in politically sensitive discussions? Relevant topics of further research also include the analysis of the features of successful versus unsuccessful argument strategies. Finally, the above questions could also be addressed in comparative studies examining the ways in which argumentation is structured on discussion groups and other social media forums, for example, blogs.


The constructive comments of anonymous reviewers are gratefully acknowledged.

About the author

Reijo Savolainen is Professor Emeritus at the Faculty of Information Technology and Communication Sciences, Tampere University, Kanslerinrinne 1, FIN-33014 Tampere, Finland. He received his PhD from University of Tampere in 1989. His main research interests are in theoretical and empirical issues of everyday information practices. He can be contacted at Reijo.Savolainen@tuni.fi


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How to cite this paper

Savolainen, R. (2020). For or against Brexit? Justifying oppositional arguments in online discussion. Information Research, 25(3), paper 864. http://InformationR.net/ir/25-3/paper864.html (Archived by the Internet Archive at https://bit.ly/3lrfiwy)

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