## 2 Related Works  
Telling which news is true or false is somehow a forced simplification of a multi-faceted problem, since we must encompass a substantial number of different bad information practices, ranging from fake news to propaganda, lies, conspiracies, rumours, hoaxes, hyperpartisan content, falsehoods or manipulated media. Information pollution is therefore not entirely made of totally fabricated contents, but rather of many shades of truth stretches. This complexity adds to the variety of styles and reputation of the writing sources, making it hard to tell misleading contents from accurate news. Given that users' time and attention are limited [18], and an extensive fact-checking and source comparison is impossible on large scale, we must rely on heuristics to quickly evaluate a news piece even before reading it. [PERSON] et al. [19] showed that users online decide on the credibility of a news article by evaluating contextual clues. An important factor is the source of the article, as pointed out by [PERSON] et al. [20], who found that both the source (i.e., the website an article is taken from) and the author of the social media post that shares the article have a heavy impact on readers' judgement of the news. Additionally, [PERSON] et al. [21] investigated the role of the website that news is taken from, finding that most people are capable of telling a mainstream news website from a low-credibility one just by looking at them. Attribution of credibility by the source is a well-documented practice in scientific literature. Due to the impossibility of fact-checking every news article, researchers have often relied on blacklists of low-credibility websites, curated by debunking organisations, in order to classify disinformation content [22; 23; 24; 25]. [PERSON] et al. [5] state that they \"advocate focusing on the original sources--the publishers--rather than individual stories, because we view the defining element of fake news to be the intent and processes of the publisher\". In fact, the malicious intentionality of the publisher is a distinctive characteristic of disinformation activities [1]. The perception of the source can also depend on personal biases: [PERSON] et al. [26] showed that sceptical and cynical users tended to attribute more credibility to citizen journalism websites than to mainstream news websites. [PERSON] et al. [27] also pointed out that the credibility of an article is influenced by the believed expertise of the source, which in turn is affected by previous psychological biases of the reader, such as in-group identity and the bandwagon effect. In fact, other people's judgement has also been shown to produce an observable effect on individual perception of a news item [28; 29]. [PERSON] et al. [30] showed that people's judgement can be influenced by other readers' reactions to news, and that others' comments significantly affected one's personal opinion. [PERSON] et al. [31] found that posts with negative comments from other people discourage users to share them. As noted by [PERSON] et al. [32], while negative comments can make an article appear less convincing to the readers, the same does not apply for a high or low number of likes alone. For an up-to-date review of the existing literature on 'fake news'-related research problems, see [33]. **Our contribution:** In our experiment, we aimed to capture how the reader's decision process on the credibility of online news is modified by some of the above-mentioned contextual features, which one was more effective on readers' mind, and on whom. We launched Fakenewslab (available at [[http://www.fakenewslab.it](http://www.fakenewslab.it)]([http://www.fakenewslab.it](http://www.fakenewslab.it)) accessed on 29 August 2022), an artificial online interactive news outlet designed to test different scenarios of credibility evaluation. We presented a sequence of 20 articles to volunteers, showing the articles to each user in five distinct ways.