Social bots – partially or fully automated accounts on social media platforms – have not only been widely discussed, but have also entered political, media and research agendas. However, bot detection is not an exact science. Quantitative estimates of bot prevalence vary considerably and comparative research is rare. We show that findings on the prevalence and activity of bots on Twitter depend strongly on the methods used to identify automated accounts. We search for bots in political discourses on Twitter, using (...) three different bot detection methods: Botometer, Tweetbotornot and “heavy automation”. We drew a sample of 122,884 unique user Twitter accounts that had produced 263,821 tweets contributing to five political discourses in five Western democracies. While all three bot detection methods classified accounts as bots in all our cases, the comparison shows that the three approaches produce very different results. We discuss why neither manual validation nor triangulation resolves the basic problems, and conclude that social scientists studying the influence of social bots on communication and discourse dynamics should be careful with easy-to-use methods, and consider interdisciplinary research. (shrink)

Hearsay or indirect testimony receives little discussion even today in epistemology, and yet it represents one of the cardinal modes for the transmission of knowledge and for human cognitive development. It suffices to think of school education whereby a student listens to teachers reporting knowledge acquired, often indirectly, from the most varied sources such as text books, newspapers, personal memory, television, etc… Or let us consider the importance of oral tradition in the social and cultural development of civilisations. Or even (...) let us call to mind the learning process of infants who, only thanks to the knowledge learned from others, succeed in learning the language. Finally, with the emerging digital technology, the information gleaned from third parties is influencing the creation of knowledge in a full gamut of fields, in a quasi-comprehensive manner. This leads us to claim that hearsay, despite the reductionist conceptual scheme to which epistemology has confined it in that indirect testimony, is in any case quintessential in the dissemination of knowledge. This work fully expounds upon the basic mechanism of indirect testimonial transmission and provides an epistemologically founded explanation of the cognitive possibilities of hearsay by investigating, in the light of the anti-reductionist paradigm, three mutually connected epistemic properties, namely trust, reputation and coherence, that are key in the epistemic justification of the truth acquired via an indirect testimony. (shrink)

We owe our first graphic experiences to Neanderthal Man, who introduced to the cultural baggage of the genus Homo two metaphorical behaviors that are fundamental in terms of their innovation: one concerns the preservation of the bodies of the dead through burial, the other is the making of signs, which in this stage of evolution do not yet represent recognizable subjects but only lines. This attests to the creation of a graphical tool that materializes and makes visible that which exists (...) in the mind, something that is other than itself, thus providing signs of a communication that unfortunately today we cannot define semantically. We cannot say whether these linear marks are a sort of «brand» or if they are carriers of meanings, however, we can observe that, with the Neanderthals, a conceptual, projectual plan exists that enables the measurement of space and the configuration of a regular rhythm, creating an original condition of movement and an association of potentially dynamic lines. (shrink)

Figurative experience, as a codified system of images, emerges in Europe about 40.000 years ago. Together with the development of a figurative system, Homo sapiens acquired his modern cognitive architecture: an entirely articulated language, as well-developed as our current phonological system is, and others cognitive capacities such as basic drawing skills, self-consciousness and group cohesiveness. “Making sign”, as a complex nonverbal symbolism, is a crucial stage in human evolution: a stage of complex symbolism by means of a non-verbal language. Its (...) value is both eidetic, when it aims at producing metaphoric and shared images, and individual, when it is involved in individual performances, that do not imply spectators. (shrink)

A novel and versatile polarization-entanglement scheme is adopted to investigate the violation of the EPR local realism for a non-maximally entangled two-photon system according to the recent nonlocality proof by Lucien Hardy. In this context the adoption of a sophisticated detection method allows direct determination of any element of physical reality (viz., determined with probability equal to unity in the words of Einstein, Podolsky and Rosen) for the pair system within complete measurements that are largely insensitive to the detector quantum-efficiencies (...) and noise. (shrink)

A reflexão sobre a proximidade do pesquisador com seu objeto empírico de pesquisa, no caso as cenas musicais do rock independente de Porto Alegre e Montevidéu, surge a partir da noção de psicanálise do conhecimento objetivo, de Gaston Bachelard. Através de questionamentos teóricos críticos, o autor propõe a apreensão poética das realidades objetivas da pesquisa, onde a musicalidade é percebida como potencial metodológico no universo da observação participante.