Credibility is of vital importance to politicians. It particularly applies to democracies, since the electoral success of parties and politicians representing them, is dependent on the trust the voters place in them. If the voters trust the politicians, they deem them credible.1 When a politician's or party's trustworthiness is in serious doubt, it is usually when their credibility is in question. Plagiarism scandals surrounding dissertations or unfair advantages concerning particular individuals, lead to public debates over the trustworthiness of politicians. The pursuit for credibility is even more urgent for these politicians.
It is undisputable that the credibility and trustworthiness of institutions, political parties and politicians are vitally important for society to function well. Trust attributions are relevant on a macro, meso and micro level.2 However, in this article it is assumed that trust attributions are prototypical of individual politicians on a micro level.
Evaluation of individuals influence the assessment of the party
The transfer of trust attributions from individual politicians to their whole relative party seems likely. It may be possible to presume that the public initially judges individual politicians as "credible" or "not credible" and that this assessment plays an essential role in the positive or negative evaluation of the individual's party. This presumption should not be misunderstood as applicable to all cases, as an "if-then-conclusion". Rather, the fundamental importance of a positive and credible image of individual politicians for their parties, shall be pinpointed. This link can also be found in the key word "personalization".3 Credibility processes on the micro level are of key interest in this article. The majorities of citizens often don't know individual politicians personally, but perceive them via a controlled (in-direct) mass media. Such mediated communication processes are also included in the focus of this article.
The actions of politicians and the comparison of their words and actions are likely the ultimate measurement of long-term credibility according to citizens.
The main questions here are: Which patterns and forms of communication particularly promote credibility? How do observers (here referred to as recipients4) determine a politician's credibility, if their statements and communication style is shown solely via mass media? Undoubtedly, a politician's credibility is by no means exclusively determined by their communication and statements. The actions of politicians and the comparison of their words and actions are likely the ultimate measurement of long-term credibility according to citizens. Nonetheless, linguistic features which with the most potential for creating credibility shall be considered.
Four dimensions of credibility
Credibility is first of all an abstract concept. To make it accessible for analysis, it must be operationalised.5 Simplified, the following four dimensions (or factors) of credibility can be identified: expertise; social embeddedness/sympathy; reputation/reliability; understandability.6 It should be noted, that not only is expertise or reputation crucial, but that all four factors affect credibility.
How can these dimensions of communication processes – whether via the media or face-to-face – be nailed down? In order to determine whether and how a speaker emphasises their expertise and reliability etc., the dimensions or factors need to be assigned to observable indicators. A competence indicator could be the naming of evidence.7 An understandability indicator could be pictorial language. Ultimately, an observer considers a political spokesman as credible, when he perceives concrete signs (indicators) of competence, social integration and reliability etc.
Indicators (signs of credibility) can be verbal, para-verbal and non-verbal features and are embedded in the speaker's phrasing. In other words, a speaker's conversational style consists of very different characteristics and some of them may be potential credibility markers. For example, it may be characteristic of a speaker to communicate using very pictorial language. As there are several communicative forms, which can potentially serve as credibility indicators, the key point for credibility is that the conversational style is coherent and consistent.
The speaker can place more emphasis on certain credibility dimensions than others, but the recipient could perceive and interpret them differently. The trust constitution and attribution is not just a double-sided communication process, you also have to consider the different perspectives of the individuals involved.
Now the question remains unanswered: Which communicative forms within mass media do the recipients consider to be particularly credible? The people believe politicians are especially credible when they communicate in a citizen-friendly way and are easily understood by the average person. Citizen-friendly communication manifests in very different forms. For example, it includes varied (and non-monotonic) intonation, every-day-life examples or the use of personal pronouns.
Less positively, however, are too-frequently used references and fixations towards a respective party or on themselves, and noticeably trying to improve their image. Recipients perceivecommon political language features, as "self-promotion", and as less conducive to the speaker’s credibility. It is even more surprising that such patterns remain consistent in political debates.
This delineation gives an initial overview of the results of a language and communication science study. The conversational style of three politicians during a radio discussion was analysed, based on 15 interviews with recipients. Although the results are not representative, they show clear trends for credibility-enhancing forms of communication.
It is apparent that the politician's verbally marked turn to the recipient or citizens and thus emphasising his social embedding is an crucial factor for his credibility together with an understandable way communication.
The following shows the diverse communicative credibility indicators:
It should be pointed out once again, that the aim here is not to create a catalogue applicable to every single political speaker, and it is not to be used as a blue print for those wishing to appear credible either. Instead, the various forms of communication, which promote credibility, are outlined. Above all, Kuhnhenn's study (2014) shows that credibility indicators exist in mutual relations.
Further reading: Kuhnhenn, Martha: Glaubwürdigkeit in der politischen Kommunikation. Gesprächsstile und ihre Rezeption, Constance 2014.
 Cf. e.g. McLean, James: Inside the NDP war room. Competing for credibility in a federal election, Montreal/Kingston 2012.
 The macro level includes the society or sections. The meso level includes institutions and organisations and the micro level includes individuals or groups.- Cf. Jarren, Otfried; Donges, Patrick: Politische Kommunikation in der Mediengesellschaft. Eine Einführung, 3rd edition, Wiesbaden 2011.
 Further reading on the processes of personalisation in politics cf. Jackob, Nikolaus: Wahlkampfkommunikation als Vertrauenswerbung – Einführung anstelle eines Vorwortes, in: Jackob, Nikolaus (ed.): Wahlkämpfe in Deutschland. Fallstudien zur Wahlkampfkommunikation 1912-2005, Wiesbaden 2007, pp. 11-33.
 The term "recipient" refers to "listener"/"reader" of mass media communication. Nevertheless the use of "listener"/"reader" should be avoided, because the concepts imply a passive role of a person. But in this context you cannot speak of passivity, because the recipient accredits the speaker with credibility in an active way.
 Research operationalisations are an explicit definition of other concepts.- Friedrich, Jürgen: Methoden der empirischen Sozialwissenschaft, 14th edition, Opladen 1990, p. 77.
 Cf. e.g. one early study regarding credibility Hovland, Carl et al.: The influence of source credibility on communication effectiveness, in: The Public Opinion Quarterly, Oxford/Cary/Tokyo/Beijing 1951, Vol. 15, No. 4, pp. 635-650.
 A piece of evidence is a plausible finding in the present context, including figures, data and facts (see also Figure 2).