A rapidly increasing number of Web databases are now become accessible via their HTML form- based query interfaces only. Comparing various services or products from a number of web sites in a specific domain is time-consuming and tedious. There is a demand for value-added Web applications that integrate data from multiple sources. To facilitate the development of such applications, we need to develop techniques for automating the process of providing integrated access to a multitude of database-driven Web sites, and integrating data from their underlying databases. This presents three challenges, namely query form extraction, query form matching and translation, and Web query result extraction. In this thesis, 1 focus on Web query result extraction, which aims to extract structured data encoded in semi-structured HTML pages, and return extracted data in relational tables. 1 begin by reviewing the existing approaches for Web query result extraction. 1 categorize them based on their degree of automation, i.e. manual, semi-automatic and fully automatic approaches. For each category, every approach will be described in terms of its technical features, followed by an analysis listing the advantages and limitations of the approach. The literature review leads to my proposed approaches, which resolve the Web data extraction problem, i.e. Web data record extraction, Web data alignment and Web data annotation. Each approach is presented in a chapter which includes the methodology, experiment and related work. The last chapter concludes the thesis.

Four experiments were conducted to test whether peak-end rule replicates in the web environment. The current enjoyment tool (CET) was developed to capture real-time enjoyment ratings. Experiment 1 mainly tested the effect of the task order- and the tool on retrospective assessments. The results showed that the tool did not influence participants’ judgments. Using the number of links to determine task difficulty was not found to be a very effective measure of enjoyment. Experiment 2 further tested the peak-end rule using a free-browsing style. The results showed that peak and end enjoyment moments were relatively low predictors of retrospective assessment, compared with the combination of a wider range of moments. The E2 results also demonstrated that duration did not correlate with either the real-time enjoyment moments or retrospective assessment of enjoyment. Experiment 3 focused on the effect of manipulating the order of selected sections of a website on retrospective assessments of enjoyment. This experiment was performed in two phases, and succeeded in controlling the flow of enjoyment; at least end enjoyment. The results indicated that increasing enjoyment towards the end would result in correspondingly higher retrospective assessment ratings of enjoyment; the converse being the case when decreasing enjoyment towards the end. Peak- and end real-time enjoyment were found to be good predictors of the retrospective assessment of enjoyment. The fourth experiment further investigated this end effect on retrospective assessments. Its design succeeded in manipulating the creation of low, medium and high end real-time enjoyment. The results showed that the high-end group recorded higher enjoyment retrospective assessments than the low-end and medium-end groups. Peak and end real-time enjoyment moments, as well as other real-time enjoyment moments (initial-, average-, and total-) in addition to procedure duration, resulted in a low prediction of retrospective assessment.

Web directories are hierarchically organised website collections that offer users subjectbased access to the Web. They played a significant part in navigating the Web in the past but their role has been weakened in recent years due to their cumbersome expanding collections. This thesis presents a unified framework combining the advantages of personalisation and redefined directory search for improving the usability of Web directories. The thesis begins with an examination of classification schemes that identifies the rigidity of hierarchical classifications and their suitability for Web directories in contrast to faceted classifications. This leads on to an Ontological Sketch Modelling (OSM) case study which identifies the misfits affecting user navigation in Web directories from known rigidity issues. The thesis continues with a review of personalisation techniques and a discussion of the user search model of Web directories following the suggested directions of improvement from the case study. A proposed user-centred framework to improve the usability of Web directories which consists of an individual content-based personalisation model and a redefined search model is then implemented as D-Persona and D-Search respectively. The remainder of the thesis is concerned with a usability test of D-Persona and D-Search aimed at discovering the efficiency, effectiveness and user satisfaction of the solution. This involves an experimental design, test results and discussions for the comparative user study. This thesis extracts a formal definition of the rigidity of hierarchies from their characteristics and justifies why hierarchies are still better suited than facets in organising Web directories. Second, it identifies misfits causing poor usability in Web directories based on the discovered rigidity of hierarchies. Third, it proposes a solution to tackle the misfits and improve the usability of Web directories which has been experimentally proved to be successful.

Ontology, an explicit specification of a shared conceptualisation, captures knowledge about a specific domain of interest. The realisation of ontologies, revolutionised the way data stored in relational databases is accessed and manipulated through ontology and database integration. When integrating ontologies with relational databases, several choices exist regarding aspects such as database implementation, ontology language features, and mappings. However, it is unclear which aspects are relevant and when they affect specific choices. This imposes difficulties in deciding which choices to make and their implications on ontology and database integration solutions. Within this study, a decision-making tool that guides users when selecting a technology and developing a solution that integrates ontologies with relational databases is developed. A theory analysis is conducted to determine current status of technologies that integrate ontologies with databases. Furthermore, a theoretical study is conducted to determine important features affecting ontology and database integration, ontology language features, and choices that one needs to make given each technology. Based on the building blocks stated above, an artifact-building approach is used to develop the decision-making tool, and this tool is verified through a proof-of-concept to prove the usefulness thereof. Key terms: Ontology, semantics, relational database, ontology and database integration, mapping, Web information portal. / Information Science / M. Sc. (Information Systems)

Ontology, an explicit specification of a shared conceptualisation, captures knowledge about a specific domain of interest. The realisation of ontologies, revolutionised the way data stored in relational databases is accessed and manipulated through ontology and database integration. When integrating ontologies with relational databases, several choices exist regarding aspects such as database implementation, ontology language features, and mappings. However, it is unclear which aspects are relevant and when they affect specific choices. This imposes difficulties in deciding which choices to make and their implications on ontology and database integration solutions. Within this study, a decision-making tool that guides users when selecting a technology and developing a solution that integrates ontologies with relational databases is developed. A theory analysis is conducted to determine current status of technologies that integrate ontologies with databases. Furthermore, a theoretical study is conducted to determine important features affecting ontology and database integration, ontology language features, and choices that one needs to make given each technology. Based on the building blocks stated above, an artifact-building approach is used to develop the decision-making tool, and this tool is verified through a proof-of-concept to prove the usefulness thereof. Key terms: Ontology, semantics, relational database, ontology and database integration, mapping, Web information portal. / Information Science / M. Sc. (Information Systems)