704 research outputs found
Using the quantum probability ranking principle to rank interdependent documents
No full textA known limitation of the Probability Ranking Principle (PRP) is that it does not cater for dependence between documents. Recently, the Quantum Probability Ranking Principle (QPRP) has been proposed, which implicitly captures dependencies between documents through “quantum interference”. This paper explores whether this new ranking principle leads to improved performance for subtopic retrieval, where novelty and diversity is required. In a thorough empirical investigation, models based on the PRP, as well as other recently proposed ranking strategies for subtopic retrieval (i.e. Maximal Marginal Relevance (MMR) and Portfolio Theory(PT)), are compared against the QPRP. On the given task, it is shown that the QPRP outperforms these other ranking strategies. And unlike MMR and PT, one of the main advantages of the QPRP is that no parameter estimation/tuning is required; making the QPRP both simple and effective. This research demonstrates that the application of quantum theory to problems within information retrieval can lead to significant improvements
Formulating XML-IR Queries
No full textXML information retrieval systems differ from traditional information retrieval systems\ud
by returning relevant portions of documents, rather than entire documents.\ud
Theoretically, this should better fulfil the information needs of users, especially in\ud
situations where their information need is very complex. However, if users are going\ud
to exploit this advantage then they need a query formation interface that is both\ud
sophisticated and intuitive. This paper outlines four potential query formation\ud
interfaces: keywords, formal language, natural language and query by templates. For\ud
each interface it: outline the advantages and disadvantages, presents comparative\ud
results stemming from experiments and proposes several future research areas\ud
involving the four interfaces
Developing the quantum probability ranking principle
No full textIn this work, we summarise the development of a ranking principle based on quantum probability theory, called the Quantum Probability Ranking Principle (QPRP), and we also provide an overview of the initial experiments performed employing the QPRP. The main difference between the QPRP and the classic Probability Ranking Principle, is that the QPRP implicitly captures the dependencies between documents by means of quantum interference". Subsequently, the optimal ranking of documents is not based solely on documents' probability of relevance but also on the interference with the previously ranked documents. Our research shows that the application of quantum theory to problems within information retrieval can lead to consistently better retrieval effectiveness, while still being simple, elegant and tractable
Information Scent, Searching and Stopping: Modelling SERP Level Stopping Behaviour
No full textCurrent models and measures of the Interactive Information Retrieval (IIR) process typically assume that a searcher will always examine the first snippet in a given Search Engine Results Page (SERP), and then with some probability or cutoff, he or she will stop examining snippets and/or documents in the ranked list (snippet level stopping). Prior work has however shown that searchers will form an initial impression of the SERP, and will often abandon a page without clicking on or inspecting in detail any snippets or documents. That is, the information scent affects their decision to continue. In this work, we examine whether considering the information scent of a page leads to better predictions of stopping behaviour. In a simulated analysis, grounded with data from a prior user study, we show that introducing a SERP level stopping strategy can improve the performance attained by simulated users, resulting in an increase in gain across most snippet level stopping strategies. When compared to actual search and stopping behaviour, incorporating SERP level stopping offers a closer approximation than without. These findings show that models and measures that naïvely assume snippets and documents in a ranked list are actually examined in detail are less accurate, and that modelling SERP level stopping is required to create more realistic models of the search process
An analysis of the cost and benefit of search interactions
No full textInteractive Information Retrieval (IR) systems often provide various features and functions, such as query suggestions and relevance feedback, that a user may or may not decide to use. The decision to take such an option has associated costs and may lead to some benefit. Thus, a savvy user would take decisions that maximises their net benefit. In this paper, we formally model the costs and benefits of various decisions that users, implicitly or explicitly, make when searching. We consider and analyse the following scenarios: (i) how long a user's query should be? (ii) should the user pose a specific or vague query? (iii) should the user take a suggestion or re-formulate? (iv) when should a user employ relevance feedback? and (v) when would the "find similar" functionality be worthwhile to the user? To this end, we build a series of cost-benefit models exploring a variety of parameters that affect the decisions at play. Through the analyses, we are able to draw a number of insights into different decisions, provide explanations for observed behaviours and generate numerous testable hypotheses. This work not only serves as a basis for future empirical work, but also as a template for developing other cost-benefit models involving human-computer interaction
Advances in formal models of search and search behaviour
No full textSearching is performed in the context of a task and as such the value of the information found is with respect to the task. Recently, there has been a drive to developing formal models of information seeking and retrieval that consider the costs and benefits arising through the interaction with the interface/system and the information surfaced during that interaction. In this full day tutorial we will focus on describing and explaining some of the more recent and latest formal models of Information Seeking and Retrieval. The tutorial is structured into two parts. In the first part we will present a series of models that have been developed based on: (i) economic theory, (ii) decision theory (iii) game theory and (iv) optimal foraging theory. The second part of the day will be dedicated to building models where we will discuss different techniques to build and develop models from which we can draw testable hypotheses from. During the tutorial participants will be challenged to develop various formals models, applying the techniques learnt during the day. We will then conclude with presentations on solutions followed by a summary and overview of challenges and future directions. This tutorial is aimed at participants wanting to know more about the various formal models of information seeking, search and retrieval, that have been proposed. The tutorial will be presented at an intermediate level, and is designed to support participants who want to be able to understand and build such models
An Analysis of Theories of Search and Search Behavior
No full textTheories of search and search behavior can be used to glean insights and generate hypotheses about how people interact with retrieval systems. This paper examines three such theories, the long standing Information Foraging Theory, along with the more recently proposed Search Economic Theory and the Interactive Probability Ranking Principle. Our goal is to develop a model for ad-hoc topic retrieval using each approach, all within a common framework, in order to (1) determine what predictions each approach makes about search behavior, and (2) show the relationships, equivalences and differences between the approaches. While each approach takes a different perspective on modeling searcher interactions, we show that under certain assumptions, they lead to similar hypotheses regarding search behavior. Moreover, we show that the models are complementary to each other, but operate at different levels (i.e., sessions, patches and situations). We further show how the differences between the approaches lead to new insights into the theories and new models. This contribution will not only lead to further theoretical developments, but also enables practitioners to employ one of the three equivalent models depending on the data available
A Framework for Emotion-aware Recommender Systems supporting Decision Making
No full textEmotions influence ever yday decisions. When people make decisions about movies to watch, songs to listen or even about more serious issues such as health, they perform a cognitive process that estimates which of various alternative choices would yield the most positive consequences. Indeed, this process in not totally rational because it is influenced, directly or in a subtle way by personality traits and emotions. In this paper we propose the idea of defining an affective user profile , which can act as a computational model of personality and emotions, included in a g eneral, affective-aware , recommendation framework
Special Issue on the Second International Conference on the Theory of Information Retrieval (ICTIR 2009)
No full textSix journal papers extended from conference papers of ICTIR 2009
Adaptive query-based sampling of distributed collections
No full textAs part of a Distributed Information Retrieval system a de-scription of each remote information resource, archive or repository is usually stored centrally in order to facilitate resource selection. The ac-quisition ofprecise resourcedescriptionsistherefore animportantphase in Distributed Information Retrieval, as the quality of such represen-tations will impact on selection accuracy, and ultimately retrieval per-formance. While Query-Based Sampling is currently used for content discovery of uncooperative resources, the application of this technique is dependent upon heuristic guidelines to determine when a sufficiently accurate representation of each remote resource has been obtained. In this paper we address this shortcoming by using the Predictive Likelihood to provide both an indication of thequality of an acquired resource description estimate, and when a sufficiently good representation of a resource hasbeen obtained during Query-Based Sampling
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