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Rui Sampaio

Abstract

According to an influential epistemological tradition, science explains phenomena on the basis of laws, but the last two decades have witnessed a neo-mechanistic movement that emphasizes the fundamental role of mechanism-based explanations in science, which have the virtue of opening the “black box” of correlations and of providing a genuine understanding of the phenomena. Mechanisms enrich the empirical content of a theory by introducing a new set of variables, helping us to make causal inferences that are not possible on the basis of macro-level correlations (due to well-known problems regarding the underdetermination of causation by correlation). However, the appeal to mechanisms has also a methodological price. They are vulnerable to interference effects; they also face underdetermination problems, because the available evidence often allows different interpretations of the underlying structure of a correlation; they are strongly context-dependent and their individuation as causal patterns can be controversial; they present specific testability problems; finally, mechanism-based extrapolations can be misleading due to the local character of mechanisms. At any rate, the study of mechanisms is an indispensable part of the human sciences, and the problems that they raise can be controlled by quantitative and qualitative methods, and an epistemologically informed exercise of critical thinking.

Open access

Bruno Gonçalves, Hugo Folgado, Diogo Coutinho, Rui Marcelino, Del Wong, Nuno Leite and Jaime Sampaio

Abstract

Success in soccer is much dependent on how players and teams create and restrict space and time. In match situations, players constitute small sub-groups to improve their collective synchronization and achievement of specific goals. This study aimed to identify changes in the effective playing space (EPS, defined as the smallest polygonal area delimited by the peripheral outfield players) when considering sub-groups of 3 to 10 players. Twenty outfield professional players participated in this study. The EPS, its regularity pattern (measured by the approximate entropy), coefficient of variation and players’ mean speed were calculated for sub-groups of 3, 4, 5, 6, 7, 8, 9 and 10 players, considering the smallest inter-player distance as the criterion. The EPS presented a most likely increase with a higher number of players, especially considering the transition from 3 to 4 players (~440% of variation, very large). As the EPS increased with the number of players, the correspondent regularity presented a trend of a most likely increase (from EPS3 vs. EPS4: ~25%, very large; to EPS9 vs. EPS10: ~11%, moderate). The mean speed results suggest that players may achieve different states of collective coordination, mainly between ~6 to 8 km.h-1. Overall, three different match scenarios should require additional attention when aiming to design more match transferable tasks: i) transition from EPS3 to EPS4; ii) transition from EPS4 up to EPS8; and iii) transition from EPS8 to EPS9. These results help to understand match self-organized behaviours and, consequently, allow to optimize task characteristics in practice sessions.