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

Supporting polyrepresentation in a quantum-inspired geometrical retrieval framework

The relevance of a document has many facets, going beyond the usual topical one, which have to be considered to satisfy a user's information need. Multiple representations of documents, like user-given reviews or the actual document content, can give evidence towards certain facets of relevance. In this respect polyrepresentation of documents, where such evidence is combined, is a crucial concept to estimate the relevance of a document. In this paper, we discuss how a geometrical retrieval framework inspired by quantum mechanics can be extended to support polyrepresentation. We show by example how different representations of a document can be modelled in a Hilbert space, similar to physical systems known from quantum mechanics. We further illustrate how these representations are combined by means of the tensor product to support polyrepresentation, and discuss the case that representations of documents are not independent from a user point of view. Besides giving a principled framework for polyrepresentation, the potential of this approach is to capture and formalise the complex interdependent relationships that the different representations can have between each other

An analytical inspection framework for evaluating the search tactics and user profiles supported by information seeking interfaces

Searching is something we do everyday both in digital and physical environments. Whether we are searching for books in a library or information on the web, search is becoming increasingly important. For many years, however, the standard for search in software has been to provide a keyword search box that has, over time, been embellished with query suggestions, Boolean operators, and interactive feedback. More recent research has focused on designing search interfaces that better support exploration and learning. Consequently, the aim of this research has been to develop a framework that can reveal to designers how well their search interfaces support different styles of searching behaviour.The primary contribution of this research has been to develop a usability evaluation method, in the form of a lightweight analytical inspection framework, that can assess both search designs and fully implemented systems. The framework, called Sii, provides three types of analyses: 1) an analysis of the amount of support the different features of a design provide; 2) an analysis of the amount of support provided for 32 known search tactics; and 3) an analysis of the amount of support provided for 16 different searcher profiles, such as those who are finding, browsing, exploring, and learning. The design of the framework was validated by six independent judges, and the results were positively correlated against the results of empirical user studies. Further, early investigations showed that Sii has a learning curve that begins at around one and a half hours, and, when using identical analysis results, different evaluators produce similar design revisions.For Search experts, building interfaces for their systems, Sii provides a Human-Computer Interaction evaluation method that addresses searcher needs rather than system optimisation. For Human-Computer Interaction experts, designing novel interfaces that provide search functions, Sii provides the opportunity to assess designs using the knowledge and theories generated by the Information Seeking community. While the research reported here is under controlled environments, future work is planned that will investigate the use of Sii by independent practitioners on their own projects

From social tagging to polyrepresentation: a study of expert annotating behavior of moving images

Mención Internacional en el título de doctorThis thesis investigates “nichesourcing” (De Boer, Hildebrand, et al., 2012), an emergent initiative of cultural heritage crowdsoucing in which niches of experts are involved in the annotating tasks. This initiative is studied in relation to moving image annotation, and in the context of audiovisual heritage, more specifically, within the sector of film archives. The work presents a case study of film and media scholars to investigate the types of annotations and attribute descriptions that they could eventually contribute, as well as the information needs, and seeking and searching behaviors of this group, in order to determine what the role of the different types of annotations in supporting their expert tasks would be. The study is composed of three independent but interconnected studies using a mixed methodology and an interpretive approach. It uses concepts from the information behavior discipline, and the "Integrated Information Seeking and Retrieval Framework" (IS&R) (Ingwersen and Järvelin, 2005) as guidance for the investigation. The findings show that there are several types of annotations that moving image experts could contribute to a nichesourcing initiative, of which time-based tags are only one of the possibilities. The findings also indicate that for the different foci in film and media research, in-depth indexing at the content level is only needed for supporting a specific research focus, for supporting research in other domains, or for engaging broader audiences. The main implications at the level of information infrastructure are the requirement for more varied annotating support, more interoperability among existing metadata standards and frameworks, and the need for guidelines about crowdsoucing and nichesourcing implementation in the audiovisual heritage sector. This research presents contributions to the studies of social tagging applied to moving images, to the discipline of information behavior, by proposing new concepts related to the area of use behavior, and to the concept of “polyrepresentation” (Ingwersen, 1992, 1996) applied to the humanities domain.Esta tesis investiga la iniciativa del nichesourcing (De Boer, Hildebrand, et al., 2012), como una forma de crowdsoucing en sector del patrimonio cultural, en la cuál grupos de expertos participan en las tareas de anotación de las colecciones. El ámbito de aplicación es la anotación de las imágenes en movimiento en el contexto del patrimonio audiovisual, más específicamente, en el caso de los archivos fílmicos. El trabajo presenta un estudio de caso aplicado a un dominio específico de expertos en el ámbito audiovisual: los académicos de cine y medios. El análisis se centra en dos aspectos específicos del problema: los tipos de anotaciones y atributos en las descripciones que podrían obtenerse de este nicho de expertos; y en las necesidades de información y el comportamiento informacional de dicho grupo, con el fin de determinar cuál es el rol de los diferentes tipos de anotaciones en sus tareas de investigación. La tesis se compone de tres estudios independientes e interconectados; se usa una metodología mixta e interpretativa. El marco teórico se compone de conceptos del área de estudios de comportamiento informacional (“information behavior”) y del “Marco integrado de búsqueda y recuperación de la información” ("Integrated Information Seeking and Retrieval Framework" (IS&R)) propuesto por Ingwersen y Järvelin (2005), que sirven de guía para la investigación. Los hallazgos indican que existen diversas formas de anotación de la imagen en movimiento que podrían generarse a partir de las contribuciones de expertos, de las cuáles las etiquetas a nivel de plano son sólo una de las posibilidades. Igualmente, se identificaron diversos focos de investigación en el área académica de cine y medios. La indexación detallada de contenidos sólo es requerida por uno de esos grupos y por investigadores de otras disciplinas, o como forma de involucrar audiencias más amplias. Las implicaciones más relevantes, a nivel de la infraestructura informacional, se refieren a los requisitos de soporte a formas más variadas de anotación, el requisito de mayor interoperabilidad de los estándares y marcos de metadatos, y la necesidad de publicación de guías de buenas prácticas sobre de cómo implementar iniciativas de crowdsoucing o nichesourcing en el sector del patrimonio audiovisual. Este trabajo presenta aportes a la investigación sobre el etiquetado social aplicado a las imágenes en movimiento, a la disciplina de estudios del comportamiento informacional, a la que se proponen nuevos conceptos relacionados con el área de uso de la información, y al concepto de “poli-representación” (Ingwersen, 1992, 1996) en las disciplinas humanísticas.Programa Oficial de Doctorado en Documentación: Archivos y Bibliotecas en el Entorno DigitalPresidente: Peter Emil Rerup Ingwersen.- Secretario: Antonio Hernández Pérez.- Vocal: Nils Phar