Knowledge Based Information Retrieval: A Semiotic Approach

The overall objective of this study is to analyze the document retrieval process and the main information retrieval (IR) concepts from the point of view of semiotics and design retrieval mechanisms based on the findings of the semiotic analysis of the retrieval situation. Semiotics is a discipline which studies 'sign systems' and how signs are exchanged in communication. The semiotic view of IR interaction presented in this dissertation views document retrieval as a kind of human communication process taking place in a social and cultural realm. The most important result of the semiotic model developed is the explication of the distinction between the knowledge production and transfer functions of document retrieval. The consequence of this finding is the conceptualization of the retrieval process as a dynamic and complex interplay between knowledge production and transfer tasks. It is hypothesised that, in the case of knowledge production, users of retrieval systems are interested in exploring new areas of the document collection which are not a priori known. Two knowledge based systems are developed based on the Okapi probabilistic retrieval system. The purpose of the retrieval systems designed is posited, in general terms, as to suggest the users new search areas of potential interest. This is achieved by treating the Inspec thesaurus as a semantic network, and applying a heuristic spreading activation technique to generate clusters of terms linked in the Inspec thesaurus. Each cluster or batch of terms is conceived as representing a part of the general search area defined by the initial user search terms. The main design objective here is to enable the user to identify new search areas from the term information contained in the batches. Two evaluation experiments were carried out with real users who had real information needs to test whether the batches were actually effective in defining search areas related to the original user queries and whether they were useful in pointing new areas which were potentially relevant to the users. A number of hypotheses related to the retrieval effectiveness of the knowledge based systems designed were also tested in the experiments. The main findings of the experiments indicate that: • the batches were useful in representing search domains relevant to the users' queries • in many cases the batches represented new ideas or new search domains to the users • the knowledge based systems had similar retrieval effectiveness in terms of precision as the Okapi syste

The impact of concept map visualizations on the information behavior, perceptions of performance, learning and use with novices in the information retrieval context

In examining undergraduate students in the information retrieval environment for the impact of computer generated concept maps, two primary research questions were considered: 1) what is the impact of display type on the novice searcher’s information behavior; and 2) what is the impact of different display types on the user’s perceptions of performance, knowledge and overall use of the system.Sixty participants in this experiment were given hypothetical information needs on two different medical topics (cholesterol, depression). Participants’ explored one of three interactive visualization displays using these medical topics, answered a pre- and post-test instrument and then completed a final questionnaire on their perceptions of the displays. Different types of inferential statistical tests were used to examine the research questions. When appropriate, factorial ANOVAs, mixed between-within ANOVAs, and chi square tests of independence were conducted.Five main findings resulted from this research: 1) for all display types (LIST, SOM, PFNET) there is an increase in the number of participant search terms and in the incorporation of MeSH terminology from the visualizations following exposure to those displays; 2) there is a relationship between the display type and the interface level from which PFNET participants chose terms; 3) searchers’ feelings of confidence, satisfaction, success, and relevance increased across all groups after system interaction; however, pretest feelings of confidence and satisfaction seem to be dependent upon the participant’s self-reported prior knowledge of the search topic; 4) feelings of confidence and satisfaction on the topic participants reported less pre-test knowledge on (cholesterol) shifted to match post-test ratings of confidence and satisfaction on the topic they had more pre-test knowledge on (depression); and 5) participants rated the PFNET system more visually appealing, easier to understand and more likely to be used in the future if given the option. Overall findings suggest that all displays were useful to the participants in this experiment and that the PFNET display was particularly useful for the novice searcher.Ph.D., Information Science -- Drexel University, 200

Crowdsourcing for image metadata : a comparison between game-generated tags and professional descriptors

One way to address the challenge of creating metadata for digitized image collections is to rely on user-created index terms, typically by harvesting tags from the collaborative information services known as folksonomies or by allowing the users to tag directly in the catalog. An alternative method, only recently applied in cultural heritage institutions, is Human Computation Games, a crowdsourcing tool that relies on user-agreement to create valid tags. This study contributes to the research by investigating tags (at various degrees of validation) generated by a Human Computation Game and comparing them to descriptors assigned to the same images by professional indexers. The analysis is done by classifying tags and descriptors by term-category, as well as by measuring overlap on both syntactic (matching on terms) and semantic (matching on meaning) level between the tags and the descriptors. The findings shows that validated tags tend to describe ‘artifacts/objects’ and that game-generated tags typically will represent what is in the picture, rather than what it is about. Descriptors also primarily belonged to this term-category but also had a substantial amount of ‘Proper nouns’, mainly named locations. Tags generated by the game, not validated by player-agreement, had a higher frequency of ‘subjective/narrative’ tags, but also more errors. It was determined that the exact (character-for-character) overlap i.e. the number of common terms compared to the entire pool of tags and descriptors was slightly less than 5% for all types of tags. By extending the analysis to include fuzzy (word-stem) matching, the overlap more than doubled. The semantic overlap was established with thesaurus relations between a sample of tags and descriptors and adapting this - more inclusive - view of overlap resulted in an increase in percentage of tags that were matched to descriptors. More than half of the validated tags had some thesaurus relation to a descriptor added by a professional indexer. Approximately 60% of the thesaurus relations between descriptors and valid tags were either ‘same’ or ‘equivalent’ and roughly 20% were associative and 20% were hierarchical. For the hierarchical relations it was found that tags typically describe images at a less specific level than descriptors.Joint Master Degree in Digital Library Learning (DILL

Spatial Aspects of Metaphors for Information: Implications for Polycentric System Design

This dissertation presents three innovations that suggest an alternative approach to structuring information systems: a multidimensional heuristic workspace, a resonance metaphor for information, and a question-centered approach to structuring information relations. Motivated by the need for space to establish a question-centered learning environment, a heuristic workspace has been designed. Both the question-centered approach to information system design and the workspace have been conceived with the resonance metaphor in mind. This research stemmed from a set of questions aimed at learning how spatial concepts and related factors including geography may play a role in information sharing and public information access. In early stages of this work these concepts and relationships were explored through qualitative analysis of interviews centered on local small group and community users of geospatial data. Evaluation of the interviews led to the conclusion that spatial concepts are pervasive in our language, and they apply equally to phenomena that would be considered physical and geographic as they do to cognitive and social domains. Rather than deriving metaphorically from the physical world to the human, spatial concepts are native to all dimensions of human life. This revised view of the metaphors of space was accompanied by a critical evaluation of the prevailing metaphors for information processes, the conduit and pathway metaphors, which led to the emergence of an alternative, resonance metaphor. Whereas the dominant metaphors emphasized information as object and the movement of objects and people through networks and other limitless information spaces, the resonance metaphor suggests the existence of multiple centers in dynamic proximity relationships. This pointed toward the creation of a space for autonomous problem solving that might be related to other spaces through proximity relationships. It is suggested that a spatial approach involving discrete, discontinuous structures may serve as an alternative to approaches involving movement and transportation. The federation of multiple autonomous problem-solving spaces, toward goals such as establishing communities of questioners, has become an objective of this work. Future work will aim at accomplishing this federation, most likely by means of the IS0 Topic Maps standard or similar semantic networking strategies

Evaluating Air Force Civil Engineer\u27s Current Automated Information Systems

Almost every organization has some form of information system where data is captured and stored for later use. The Air Force civil engineering organization is no exception and is in the process of transitioning from the Interim Work Information Management System (WIMS) to the Automated Civil Engineer System (ACES). This research focused on users perceptions of both database and data importance to determine if significant differences existed between various user sub-groups. The research also attempted to identify the most frequently reported problems regarding system usage. The methods of analysis of variance and content analysis were used to answer the research questions using survey responses from a sample size of 814. The results indicate that civil engineers slightly agree that their database and the data it collects are important. However, significant differences in perception levels were found between men and women, between some major commands (MAJCOMS), between users of different systems, and between personnel of different rank. Content analysis of comments in response to open-ended questions found that users are generally satisfied with their current system. However, areas of concern included slow system speed, lack of a user-friendly report writing feature, and poor reliability

Effective Knowledge Transfer: A Terminological Perspective - Dismantling The Jargon Barrier To Knowledge About Computer Security

The research is concerned with the terminological problems that computer users experience when they try to formulate their knowledge needs and attempt to access information contained in computer manuals or online help systems while building up their knowledge. This is the recognized but unresolved problem of communication between the specialist and the layman. The initial hypothesis was that computer users, through their knowledge of language, have some prior knowledge of the subdomain of computing they are trying to come to terms with, and that language can be a facilitating mechanism, or an obstacle, in the development of that knowledge. Related to this is the supposition that users have a conceptual apparatus based on both theoretical knowledge and experience of the world, and of several domains of special reference related to the environment in which they operate. The theoretical argument was developed by exploring the relationship between knowledge and language, and considering the efficacy of terms as agents of special subject knowledge representation. Having charted in a systematic way the territory of knowledge sources and types, we were able to establish that there are many aspects of knowledge which cannot be represented by terms. This submission is important, as it leads to the realization that significant elements of knowledge are being disregarded in retrieval systems because they are normally expressed by language elements which do not enjoy the status of terms. Furthermore, we introduced the notion of `linguistic ease of retrieval' as a challenge to more conventional thinking which focuses on retrieval results

Effective knowledge transfer: a terminological perspective - Dismantling the jargon barrier to knowledge about computer security

The research is concerned with the terminological problems that computer users experience when they try to formulate their knowledge needs and attempt to access information contained in computer manuals or online help systems while building up their knowledge. This is the recognised but unresolved problem of communication between the specialist and the layman. The initial hypothesis was that computer users, through their knowledge of language, have some prior knowledge of the subdomain of computing they are trying to come to terms with, and that language can be a facilitating mechanism, or an obstacle, in the development of that knowledge. Related to this is the supposition that users have a conceptual apparatus based on both theoretical knowledge and experience of the world, and of several domains of special reference related to the environment in which they operate. The theoretical argument was developed by exploring the relationship between knowledge and language, and considering the efficacy of terms as agents of special subject knowledge representation. Having charted in a systematic way the territory of knowledge sources and types, we were able to establish that there are many aspects of knowledge which cannot be represented by terms. This submission is important, as it leads to the realisation that significant elements of knowledge are being disregarded in retrieval systems because they are normally expressed by language elements which do not enjoy the status of terms. Furthermore, we introduced the notion of `linguistic ease of retrieval' as a challenge to more conventional thinking which focuses on retrieval results