Hypertext Semiotics in the Commercialized Internet

Die Hypertext Theorie verwendet die selbe Terminologie, welche seit Jahrzehnten in der semiotischen Forschung untersucht wird, wie z.B. Zeichen, Text, Kommunikation, Code, Metapher, Paradigma, Syntax, usw. Aufbauend auf jenen Ergebnissen, welche in der Anwendung semiotischer Prinzipien und Methoden auf die Informatik erfolgreich waren, wie etwa Computer Semiotics, Computational Semiotics und Semiotic Interface Engineering, legt diese Dissertation einen systematischen Ansatz für all jene Forscher dar, die bereit sind, Hypertext aus einer semiotischen Perspektive zu betrachten. Durch die Verknüpfung existierender Hypertext-Modelle mit den Resultaten aus der Semiotik auf allen Sinnesebenen der textuellen, auditiven, visuellen, taktilen und geruchlichen Wahrnehmung skizziert der Autor Prolegomena einer Hypertext-Semiotik-Theorie, anstatt ein völlig neues Hypertext-Modell zu präsentieren. Eine Einführung in die Geschichte der Hypertexte, von ihrer Vorgeschichte bis zum heutigen Entwicklungsstand und den gegenwärtigen Entwicklungen im kommerzialisierten World Wide Web bilden den Rahmen für diesen Ansatz, welcher als Fundierung des Brückenschlages zwischen Mediensemiotik und Computer-Semiotik angesehen werden darf. Während Computer-Semiotiker wissen, dass der Computer eine semiotische Maschine ist und Experten der künstlichen Intelligenz-Forschung die Rolle der Semiotik in der Entwicklung der nächsten Hypertext-Generation betonen, bedient sich diese Arbeit einer breiteren methodologischen Basis. Dementsprechend reichen die Teilgebiete von Hypertextanwendungen, -paradigmen, und -strukturen, über Navigation, Web Design und Web Augmentation zu einem interdisziplinären Spektrum detaillierter Analysen, z.B. des Zeigeinstrumentes der Web Browser, des Klammeraffen-Zeichens und der sogenannten Emoticons. Die Bezeichnung ''Icon'' wird als unpassender Name für jene Bildchen, welche von der graphischen Benutzeroberfläche her bekannt sind und in Hypertexten eingesetzt werden, zurückgewiesen und diese Bildchen durch eine neue Generation mächtiger Graphic Link Markers ersetzt. Diese Ergebnisse werden im Kontext der Kommerzialisierung des Internet betrachtet. Neben der Identifizierung der Hauptprobleme des eCommerce aus der Perspektive der Hypertext Semiotik, widmet sich der Autor den Informationsgütern und den derzeitigen Hindernissen für die New Economy, wie etwa der restriktiven Gesetzeslage in Sachen Copyright und Intellectual Property. Diese anachronistischen Beschränkungen basieren auf der problematischen Annahme, dass auch der Informationswert durch die Knappheit bestimmt wird. Eine semiotische Analyse der iMarketing Techniken, wie z.B. Banner Werbung, Keywords und Link Injektion, sowie Exkurse über den Browser Krieg und den Toywar runden die Dissertation ab

Clustering Information Retrieval Search Outputs

Users are known to have difficulties in dealing with information retrieval search outputs especially if the outputs are above a certain size. It has been argued by several researchers that search output clustering can help users in their interaction with IR systems. Clustering may provide users an overview of the output by exploiting the topicality information that resides in the output but has not been used in the retrieval stage. It can enable them to find the relevant documents more easily and also help them to form an understanding of the different facets of the query that have been provided for their Inspection. This project aimed to investigate the viability of using clustering as a way of mediating users’ interaction with search outputs and attempted to identify its possible benefits. Can&Ozkarahan’s(90) C3M algorithm was used to test the effectiveness of clustering as a way of search output presentation. C3M is a relatively simple, non-hierarchical method that has been shown to give compatible or superior results to best-known hierarchical methods. The method was implemented in TCL and linked to the department’s experimental IR system Okapi. Implementation included a procedure of term selection for document representation which preceded the clustering process and a procedure involving cluster representation for users’ viewing following the clustering process. After some tuning of the implementation parameters for the databases used, several experiments were designed and conducted to assess whether clusters could group documents in useful ways. One group of experiments aimed to assess the ability of the implementation to bring together topically related documents. It was quite difficult to gather data for such an assessment, but the existence of a set of data generated for TREC Interactive track(1996) enabled us to design experiments that at least approximately satisfied our objective. TREC provided a set of queries, and groups of relevant documents with facet assignments made by expert users. It was thus possible to make an Inference by measuring the correlation between the clusters relevant documents were assigned to and the facet assignments made for the documents by TREC experts. The utility of this data set was limited for various reasons discussed in the related chapters, however, it can be concluded that clusters cannot be relied on to bring together relevant documents assigned to a certain facet. While there was some correlation between the cluster and facet assignments of the documents when the clustering was done only on relevant documents, no correlation could be found when the clustering was based on results of queries defined by City participants to the Interactive track. Another group of experiments was conducted to compare output clustering with relevance ranking as a search output representation method. This comparison was necessary as an immediate consequence of clustering search output would be the loss of relevance ranking. It had to be assessed whether clustering could help users to find the relevant documents more easily than by relevance ranking, before any clustering solution could be proposed as an alternative to relevance ranked output. For this purpose, two sets of user experiments(n=20 and n=57) were conducted based on the users’ own information needs. While changes have been made to the implementation between the first and the second set of experiments, the experimental design was almost the same in both runs. Users were first asked to rank clusters formed from the search output(top 50 documents) and then make relevance judgements for the individual documents for the same output. The precision of cluster(s) marked best by the users were then compared to precision values that would be attained by relevance ranking at comparable thresholds. The results from the 1st group of user experiments were not conclusive(in some part due to the smallness of the data set), but they drew our attention to the importance of representation of clusters and documents for users’ viewing. After some changes to the implementation, mainly related to representation issues, and an intermediate set of 10 experiments to assess two new representation formats, a set of 57 user experiments were conducted to measure and compare precision values attainable by clustering versus relevance ranking. These experiments revealed no significant precision difference between clustered outputs and ranked lists. The number of cases where one method achieved better than the other was slightly higher for the ranked lists at the top cluster level and slightly higher for the clustered representation at the top two clusters level. However the overall average precision values were higher for the ranked list at both levels. As such, clustering did not appear to be preferable to ranked lists especially as It also represented overheads in both computing time and resources involved in creation of the clusters, and the time and effort taken by the users to inspect them. An interesting outcome of the user experiments was the ability of the users to identify clusters that do not include relevant information. There were less relevant documents among the clusters marked last by the users as compared to the documents ranked last at similar threshold levels. This brought out the possibility of using clusters as an exclusion tool to improve the precision of ranked lists. After exclusion of documents from the last cluster, ranked lists performed significantly better than the clusters at the top cluster level. There was also some evidence (consisting of observation of users during the experiments and a few user comments) that clusters could be used to provide the users with a glimpse of the search results, in order to decide whether to inspect the search results or initiate a new query straight away. In summary, cumulative experiment results imply that clustering cannot outperform relevance ranking, and seems to deserve only a secondary role in users’ interaction with IR systems. However, it should also be noted that the experiment results are not representative of the whole set of possible user types and search situations and it may be possible to Identify search situations where clustering can be more beneficial than relevance ranking

Cognitive Foundations for Visual Analytics

In this report, we provide an overview of scientific/technical literature on information visualization and VA. Topics discussed include an update and overview of the extensive literature search conducted for this study, the nature and purpose of the field, major research thrusts, and scientific foundations. We review methodologies for evaluating and measuring the impact of VA technologies as well as taxonomies that have been proposed for various purposes to support the VA community. A cognitive science perspective underlies each of these discussions

Advanced Studies on Link Proposals and Knowledge Retrieval of Hypertexts with CBR

In this paper, several problems in associating hyperlinks to text and the diverse possibilities to overcome these problems are discussed. At the current stage, an important aspect is knowledge retrieval of hypertexts. Our advanced studies on hyperlink management focus mainly on a concept similar to Case-Based Reasoning (CBR) systems as a possibility for the automatic generation of links for hypertexts in addition to traditional textual based methods. A detailed discussion of the basic ideas of CBR and an evaluation of its usefulness follows. Finally, methods to evaluate the quality of the proposals are described

Learning Basic Electrical Concepts With Models and Analogies Using a Multimedia Package

Secondary school teachers aim at helping their students to learn efficiently by using many exploratory treatments, especially in physics. Leading science educators and researchers promote learning by confronting students with the inconsistencies entailed by their own beliefs. The thesis indicates that well designed computer based environments with models and analogies can provide advantages over many approaches using other media. The facilities provided by such environments can be exploited to promote cognitive conflict which is believed to be beneficial for learning. Within the framework of using models and analogies to support learning science, the claim of the thesis is explored through: the nature of students' beliefs about electrical concepts which are in conflict with scientific beliefs the required prerequisites of computer based environments which can promote learning of these concepts through models and analogies the issues which relate to educational theory and practice, students' learning & teaching, and the design of software using HyperCard techniques and multimedia for the creation of models and analogies. Software was constructed within the framework of the design claimed by this research. Questionnaires were given to the students, and interviews and observations were made of their use of the software. With reference to the results, an analysis is included of the use of models and analogies in teaching & learning science topics. The advantages and disadvantages of these kinds of computational environments for the improvement of students' learning are discussed in details mainly with emphasis on the nature of students' beliefs, which are deeply seated and persistent. The recommendations included focus on how such environments can be designed and constructed in the near future in order to create suitable mental models for a better understanding of electrical concepts and phenomena

Weblogs 1994 – 2000: A genealogy

Using extensive fieldwork in the online archival record, this thesis accounts for the descent and emergence of the weblog as a digital genre during its formative period up to the year 2000. The work examines the weblog’s process of genre formation as diffusion of innovation within a heterogeneous discourse network. It describes this process as a series of several consecutive and cumulative reinterpretations of the emerging genre’s form and intended purpose, effected for the most part by the most central actors in the network