Preliminary Experiments using Subjective Logic for the Polyrepresentation of Information Needs

According to the principle of polyrepresentation, retrieval accuracy may improve through the combination of multiple and diverse information object representations about e.g. the context of the user, the information sought, or the retrieval system. Recently, the principle of polyrepresentation was mathematically expressed using subjective logic, where the potential suitability of each representation for improving retrieval performance was formalised through degrees of belief and uncertainty. No experimental evidence or practical application has so far validated this model. We extend the work of Lioma et al. (2010), by providing a practical application and analysis of the model. We show how to map the abstract notions of belief and uncertainty to real-life evidence drawn from a retrieval dataset. We also show how to estimate two different types of polyrepresentation assuming either (a) independence or (b) dependence between the information objects that are combined. We focus on the polyrepresentation of different types of context relating to user information needs (i.e. work task, user background knowledge, ideal answer) and show that the subjective logic model can predict their optimal combination prior and independently to the retrieval process

The pragmatics of a diachronic journal impact factor

the paper argues for a pragmatic approach to the Thomson-Reuter’s journal impact factor. The paper proposes and discusses to replace the current synchronous Thomson-Reuter journal impact factor by an up-to-date diachronic version (DJIF), consisting of a three-year citation window over a one year publication window. The DJIF online data collection and calculation is exem-plified and compared to the present synchronous journal impact factor. The paper discusses briefly the dimensions of currency, robustness, understandability and comparability to other impact factors used in research evaluation

Una teoría cognitiva integral para la recuperación de información: saliendo del entorno del laboratorio

The paper demonstrates how the Laboratory Research Framework fits into the integrated Cognitive Framework for IR. It first discusses the Laboratory Framework with emphasis on its underlying assumptions and known limitations. This is followed by a view of interaction and relevance phenomena associated with IR evaluation and central to the understanding of IR. The ensuing section outlines how interactive IR is viewed from a Cognitive Framework, and ‘light’ interactive IR experiments are suggested performed by drawing on the latter framework’s contextual possibilities. These include independent variables drawn from a collection, matching principles in a retrieval system, and the searcher’s situation and task context. The paper ends with concluding points of summarization of issues encountered.Este artículo demuestra cómo el marco de investigación en laboratorio encaja bien dentro del marco cognitivo integral para la Recuperación de información. Se discute primero el marco de investigación en laboratorio, con énfasis en sus asunciones y limitaciones. Se analizan los fenómenos de la interacción y relevancia asociados con la evaluación en RI., así como el modo de desarrollar experimentos interactivos de Recuperación de información dentro del marco cognitivo, considerando la situación del investigador y el contexto de la tarea llevada a cabo