Predyktory wiedzy i wiedza na temat COVID-19: Media społecznościowe, wiarygodność informacji, opinia publiczna i zachowanie w globalnym badaniu wielkoskalowym (*) [Predictors and outcomes of knowledge on COVID-19: Social media, information credibility, public opinion and behaviour in a large-scale global study] Yash Chawla (Department of Operations Research and Business Intelligence, PWr, Wrocław) The global spread of COVID-19 is accompanied by extensive social media coverage based on both credible and non-credible sources of information. This study explores how individuals obtain knowledge, perceive information sources and, as a consequence, behave or form opinions while facing the pandemic. We first develop a theoretical model that identifies the predictors of individuals' knowledge and the outcomes as a wide spectrum of people's behaviour and opinions. We then empirically test our model through a large-scale global survey of 15,552 respondents from 123 countries. Our results indicate that relying on one source of information does not lead to favourable behaviour towards curbing the pandemic. However, the perception of information source credibility has a significant effect on an individual's knowledge. In line with the World Health Organization, to collectively curb emergencies, we need to either educate people or control misinformation spread on policy and social network platforms. We contribute to the existing debate on the use of social media, the veracity of news, health-related communication, and people's behaviour and actions. (*) Joint work with: Agnieszka Radziwon (University of California, Berkeley, USA & Aarhus University, DEN), Laurent Scaringella (Rennes School of Business, FRA & Kozminski University, POL), Ewa Lazarczyk Carlson (Reykjavik University, ISL), Marco Greco (University of Cassino and Southern Lazio, ITA), Paulo Silveira (Polytechnic Institute of Setúbal, POR), Eduardo Aguiar (Federal University of Juiz de Fora, BRA), QingYang Shen (Chengdu University of Information Technology, CHN), Markus Will (University of Applied Sciences Zittau/Görlitz, GER), Anna Kowalska-Pyzalska (Wroclaw University of Science and Technology, POL)