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11.
Hierarchical Text Categorization (HTC) is the task of generating (usually by means of supervised learning algorithms) text classifiers that operate on hierarchically
structured classification schemes. Notwithstanding the fact that most large-sized classification schemes for text have a hierarchical
structure, so far the attention of text classification researchers has mostly focused on algorithms for “flat” classification,
i.e. algorithms that operate on non-hierarchical classification schemes. These algorithms, once applied to a hierarchical
classification problem, are not capable of taking advantage of the information inherent in the class hierarchy, and may thus
be suboptimal, in terms of efficiency and/or effectiveness. In this paper we propose TreeBoost.MH, a multi-label HTC algorithm consisting of a hierarchical variant of AdaBoost.MH, a very well-known member of the family of “boosting” learning algorithms. TreeBoost.MH embodies several intuitions that had arisen before within HTC: e.g. the intuitions that both feature selection and the selection
of negative training examples should be performed “locally”, i.e. by paying attention to the topology of the classification
scheme. It also embodies the novel intuition that the weight distribution that boosting algorithms update at every boosting
round should likewise be updated “locally”. All these intuitions are embodied within TreeBoost.MH in an elegant and simple way, i.e. by defining TreeBoost.MH as a recursive algorithm that uses AdaBoost.MH as its base step, and that recurs over the tree structure. We present the results of experimenting TreeBoost.MH on three HTC benchmarks, and discuss analytically its computational cost.
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| Fabrizio SebastianiEmail: |
12.
Lupo C Minganti C Cortis C Perroni F Capranica L Tessitore A 《Journal of sports sciences》2012,30(9):889-897
This study aimed to compare specific technical and tactical indicators of the team and centre forward role of Euro League, and Italian Serie A1, Serie A2, and Serie B men's water polo club competitions. A notational analysis was performed on 21 water polo matches to evaluate the occurrence of technical and tactical team and centre forward indicators, highlighting differences among championships according to chi-square analyses. Differences emerged for Counterattack (P < 0.001) and Power-Play (P < 0.001) possessions, Even (P < 0.001; Euro League: 3 ± 1, Serie A1: 3 ± 2, Serie A2: 3 ± 2, Serie B: 6 ± 4) and Power-Play (P = 0.001) goals, and exclusions and penalties (P = 0.008) of the team during Even possessions. Relatively to the role analyses, effects emerged for perimeter players playing events (P = 0.049), as well as for centre forwards' goals (P = 0.007) and exclusions and penalties (P < 0.001; Euro League: 8 ± 1, Serie A1: 6 ± 2, Serie A2: 6 ± 2, Serie B: 3 ± 2) occurring at the end of Even possessions. Therefore, in Euro League, and Italian Serie A1 and Serie A2, teams perform a high occurrence of Power-Play possessions following up an exclusion, especially achieved by the centre forward during Even possessions, while, in Italian Serie B, goals were mostly scored during Even possessions, with a relevant contribution from the centre forward role. 相似文献
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Two studies were carried out during university workshops, and analyzed the effects of resource interdependence on student‐student interactions, and the impact of these interactions on performance. Students worked cooperatively, either on complementary information (positive resource interdependence) or on identical information (resource independence). In Study 1, analysis of videotaped interactions revealed that working on complementary information produced more positive interactions; however this was not sufficient to prevent students who had no direct access to the information from being disadvantaged, because of informational dependence. In Study 2, with simpler texts allowing better information transmission, performance was favored when students worked on complementary information. Moreover, working on identical information not only enhanced confrontations of point of views, it also elicited competence threat. Further analysis revealed that competence threat mediated resource interdependence effect on performance. Discussion provides insights into the conditions in which different cooperative methods can benefit learning. 相似文献
15.
Céline Darnon Sébastien Doll Fabrizio Butera 《European Journal of Psychology of Education - EJPE》2007,22(3):227-242
This experiment examined the effects of epistemic vs. relational conflicts on the relationship with a partner. Students participated
to a fictitious computer-mediated interaction about a text with a bogus partner who introduced either an epistemic conflict
(a conflict that referred to the content of the text), or a relational conflict (a conflict that questioned participants’
competence). Results indicated that compared to the epistemic conflict, the relational conflict enhanced threat and reduced
the perceived contribution of the partner. Moreover, after a relational conflict, participants were more assertive in their
answers, justified them to a lower extent, and expressed less doubt than after an epistemic conflict. Results also indicated
that the intensity of disagreement predicted different modes of regulation depending on the conflict type. Finally, epistemic
conflict elicited better learning than relational conflict. 相似文献
16.
Soncini Annalisa Matteucci Maria Cristina Butera Fabrizio 《European Journal of Psychology of Education - EJPE》2021,36(3):719-738
European Journal of Psychology of Education - The present research investigated the possibility to foster positive classroom climate, achievement emotions, and adaptive beliefs about errors by... 相似文献
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This paper analyses how the existence of competitive technology markets affects firms’ technology sourcing decisions, and their propensity to enter into new product markets. While the division of innovative labour has received increasing attention within the economic literature, this paper focuses on its managerial implications. By means of a specialised database, we assess how patterns of technology trade influence firms’ technology and diversification strategies in the chemical industry. We find that, the larger the market for technology, the stronger the advantages to substitute internal R&D with outsourcing, and to increase the degree of product diversification. 相似文献
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Despite the potential benefits of cooperative learning at university, its implementation is challenging. Here, we propose a theory-based 90-min intervention with 185 first-year psychology students in the challenging domain of statistics, consisting of an exercise phase and an individual learning post-test. We compared three conditions that manipulated the exercise phase: individual work, cooperative dyadic instructions (structuring three basic components of cooperative learning: positive goal interdependence, individual responsibility and promotive interactions) and cooperative dyadic interactions (the three basic components with an additional cooperative nudge, namely explaining why and how to cooperate in this task) in order to test whether a progressive increase in benefits occurs as the cooperative structure is reinforced. Results indicated a linear trend in individual post-test learning and competence perception, from individual work to cooperative instructions to cooperative interactions. Competence perception mediated the effect of experimental conditions on learning. The results highlight the benefits of the cooperative nudge. 相似文献
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Onur Güntürkün Charlotte Koenen Fabrizio Iovine Alexis Garland Roland Pusch 《Learning & behavior》2018,46(3):229-241
We are surrounded by an endless variation of objects. The ability to categorize these objects represents a core cognitive competence of humans and possibly all vertebrates. Research on category learning in nonhuman animals started with the seminal studies of Richard Herrnstein on the category “human” in pigeons. Since then, we have learned that pigeons are able to categorize a large number of stimulus sets, ranging from Cubist paintings to English orthography. Strangely, this prolific field has largely neglected to also study the avian neurobiology of categorization. Here, we present a hypothesis that combines experimental results and theories from categorization research in pigeons with neurobiological insights on visual processing and dopamine-mediated learning in primates. We conclude that in both fields, similar conclusions on the mechanisms of perceptual categorization have been drawn, despite very little cross-reference or communication between these two areas to date. We hypothesize that perceptual categorization is a two-component process in which stimulus features are first rapidly extracted in a feed-forward process, thereby enabling a fast subdivision along multiple category borders. In primates this seems to happen in the inferotemporal cortex, while pigeons may primarily use a cluster of associative visual forebrain areas. The second process rests on dopaminergic error-prediction learning that enables prefrontal areas to connect top down the relevant visual category dimension to the appropriate action dimension. 相似文献
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Christopher Beedie Fabrizio Benedetti Diletta Barbiani Eleanora Camerone Emma Cohen Damian Coleman 《European Journal of Sport Science》2018,18(10):1383-1389
In June 2017 a group of experts in anthropology, biology, kinesiology, neuroscience, physiology, and psychology convened in Canterbury, UK, to address questions relating to the placebo effect in sport and exercise. The event was supported exclusively by Quality Related (QR) funding from the Higher Education Funding Council for England (HEFCE). The funder did not influence the content or conclusions of the group. No competing interests were declared by any delegate. During the meeting and in follow-up correspondence, all delegates agreed the need to communicate the outcomes of the meeting via a brief consensus statement. The two specific aims of this statement are to encourage researchers in sport and exercise science to
1. Where possible, adopt research methods that more effectively elucidate the role of the brain in mediating the effects of treatments and interventions.
2. Where possible, adopt methods that factor for and/or quantify placebo effects that could explain a percentage of inter-individual variability in response to treatments and intervention. 相似文献