Biotechnological applications of UV-B radiation in agri-food crops from La Rioja: grapes and mushrooms as models of quality and sustainability

From the observational methodology approach, this thesis analyses error in chess, conceived as an inherent aspect of the learning process. Errors are manifested both through illegal moves, which reflect an incomplete understanding of the rules, and through erroneous moves, associated with a lack of comprehension of the internal logic of chess. The general objective of the thesis is to analyse the difficulties that players experience during the process of learning chess. Based on this, two specific objectives are established: (1) to characterise illegal moves in introductory chess, and (2) to characterise erroneous moves in children’s competitive chess. The thesis is structured into two complementary studies, each focused on addressing one of these objectives. The first study focuses on illegal moves committed by players in the U12 category from La Rioja during the regional Sports Games competition. An ad hoc observation system was designed, based on an exhaustive analysis of the FIDE Laws of Chess, to record and classify illegal moves. The reliability of the records was ensured through Cohen’s Kappa coefficient, and the validity of the instrument was verified by applying Generalizability Theory, through two measurement designs that confirmed the consistency and generalizability of the data. Seven types of illegal moves were identified: incorrect castling, pin, moving the king into check, incorrect piece movement, pawn promotion, illegal square occupation, and failure to remove a check. The adjusted residuals analysis revealed a higher incidence of king-movement illegals (including castling), indicating conceptual difficulties related to king safety and rule comprehension, as well as the challenges posed by diagonal piece movement. The second study analyses definitive errors—those that directly lead to the loss of the game—among elite U8 players in the Spanish National Championship. A second ad hoc observation instrument was designed, combining a field format and category system, based on a theoretical review of the internal logic of chess. The games were collected using ChessBase 17 and analysed with the Stockfish 16 NNUE engine via the Lichess platform, while data coding was performed using Lince software. Inter-observer reliability was ensured through Cohen’s Kappa coefficient. Data analysis was carried out using the decision tree technique, taking the impact of the error as the dependent variable. The results show that the errors leading to defeat are mainly associated with deficiencies in short-term tactical calculation—tactical motifs, undefended pieces, or checkmate—rather than with long-term strategic planning errors. Taken together, both studies provide an empirical and systematic approach to the analysis of error in chess from an educational perspective. The findings deepen our understanding of the cognitive and conceptual difficulties faced by children and offer guidelines for designing instructional strategies tailored to their developmental level, transforming error into a learning tool and adjusting the complexity of tasks. This perspective reinforces the educational value of chess as an ideal context for fostering self-regulation, critical thinking, and reflective learning, while consolidating a pedagogical model that views error as a natural part of the learning process and as a resource for promoting reflection and informed decision-making in the game.