The article concerns the history of ethnography in Poland in the 19th century. This one illustrates that field research serves to validate theories, not to disprove them. Therefore, the article is divided into parts that relate to working in libraries, and then to searching for signs in the field for the concepts learned.

In the article I analyse the responses of Polish primary care practitioners to coronavirus pandemic. I argue that the doctors by – employing their skills and knowledge – ad hoc started to reconstruct their professional world heavily influenced by the virus. I employ a body of literature focused on risk-taking, risk society, and second modernity to shed more light on doctors` practices, who entered a risky, yet intellectually and professionally refreshing interplay with the threads brought to them by the virus.

The main purpose of the article is to analyse the learning practices of Brazilian jiu-jitsu through the Internet. The article reveals the results of the research conducted from 2016 to 2019 in one jiu-jitsu club in Warsaw, Poland. The material came mostly from the in-depth interviews, and describes the nuances, restrictions and implications of learning Brazilian jiu-jitsu from YouTube. Such form of learning becomes an „inevitably deficient” process although may lead to the „creation of hybrids” and „exploitation of the surplus” (of knowledge sources) but also may strengthen the fundamental local training regime. In the final part of the text, I present the general patterns of using YouTube in the process of learning Brazilian jiu-jitsu. In reference to the ideas of Tim Ingold I conclude that gathered data allow to present the results of mixing and knotting the particular kinds of knowledge.