In April 2009, Google Images added a filter for narrowing search results by colour. Several other systems for searching image databases by colour were also released around this time. These colour-based image retrieval systems enable users to search image databases either by selecting colours from a graphical palette (i.e., query-by-colour), by drawing a representation of the colour layout sought (i.e., query-by-sketch), or both. It was comments left by readers of online articles describing these colour-based image retrieval systems that provided us with the inspiration for this research. We were surprised to learn that the underlying query-based technology used in colour-based image retrieval systems today remains remarkably similar to that of systems developed nearly two decades ago. Discovering this ageing retrieval approach, as well as uncovering a large user demographic requiring image search by colour, made us eager to research more effective approaches for colour-based image retrieval. In this thesis, we detail two user studies designed to compare the effectiveness of systems adopting similarity-based visualisations, query-based approaches, or a combination of both, for colour-based image retrieval. In contrast to query-based approaches, similarity-based visualisations display and arrange database images so that images with similar content are located closer together on screen than images with dissimilar content. This removes the need for queries, as users can instead visually explore the database using interactive navigation tools to retrieve images from the database. As we found existing evaluation approaches to be unreliable, we describe how we assessed and compared systems adopting similarity-based visualisations, query-based approaches, or both, meaningfully and systematically using our Mosaic Test - a user-based evaluation approach in which evaluation study participants complete an image mosaic of a predetermined target image using the colour-based image retrieval system under evaluation.

The evolution of the web has outpaced itself: The growing wealth of informa- tion and the increasing sophistication of interfaces necessitate automated pro- cessing. Web automation and extraction technologies have been overwhelmed by this very growth. To a'ddress this trend, we identify four key requirements of web extraction: (1) Interact with sophisticated web application interfaces, (2) Precisely capture the relevant data for most web extraction tasks, (3) Scale with the number of visited pages, and (4) Readily embed into existing web technologies. ThIS dissertation discusses OXPATH, an extension of XPath for interacting with web applications and for extracting information thus revealed. It ad- -: dresses all the above requirements. OXPATH's page-at-a-time evaluation guar- antees memory use independent of the number of visited pages, yet remains polynomial in time. We validate experimentally the theoretical complexity and demonstrate that its evaluation is dominated by technical aspects such as the page rendering of the underlying browser. We also present OXPATH host languages, including Ox LATIN. Ox LATIN extends the well-known Pig Latin language and can run on a standard Hadoop cluster. The Ox LATIN language facilitates distributed expression evaluation in a cloud computing paradigm, providing support for common web extraction scenarios that include expression composition, aggregation, and integration. Ox LATIN adds support for continuations within its programs, which increases its efficiency by eliminating unneeded page fetches. Our experiments confirm the scalability of OXPATH and Ox LATIN. We fur- ther show that OXPATH outperforms existing commercial and academic data extraction tools by a wide margin. OXPATH is available under an open source license. We also discuss applications and ongoing tool development that establish OX- PATH as a data extraction tool that advances the state-of-the-art.

This study has investigated the search options and features teachers use and prefer to have, when personalising their online search for teaching resources. This study focused on making web searching easier for UK teacher practitioners at primary, secondary and post-compulsory levels. In this study, a triangulated mixed method approach was carried out in a two phase iterative case study involving 75 teacher practitioners working in the UK educational setting. In this case study, a sequential evidence gathering method called ‘System Development Life Cycle’ (SDLC) was adapted linking findings obtained from the structured questionnaires, observations and semi-structured interviews in order to design, develop and test two versions of an experimental search tool called “PoSTech!”. This research has contributed to knowledge by offering a model of teachers’ web information needs and search behaviour. In this model twelve search options and features mostly used by teachers when personalising their search for finding online teaching resources via the revised search tool are listed, in order of popularity. A search options is selected by the teacher and features is the characteristic of an option teachers experiences. For example, search options 'Subject', ‘Age Group’, ‘Resource Type’, ‘Free and/ Paid resources’, ‘Search results language’, and search features that ‘Store search options selected by individual teachers and their returned results’. Teachers’ model of web information needs and search behaviour could be used by the Government, teacher trainers and search engine designers to gain an insight into the information needs and search behaviours of teachers when searching for online teaching resources by means of tackling technical barriers faced by teachers, when using the internet. In conclusion, the research work presented in this thesis has provided the initial and important steps towards understanding the web searching information needs and search behaviours of individual teachers, working in the UK educational setting.

Information is a valuable commodity and its effective use is a vital part of everyday life. With the advancements of the internet and the increasing accessibility to it, the location of information is no longer the primary concern of information seekers. Digitisation techniques have made a wide variety of documents available on-line, and more and more publications are being published in electronic form simultaneously to their physical counterpart. The largest challenge currently facing information seekers is that of locating the correct information from the abundance available to them. Whenever a search query is made, the user is inundated with multiple options of documents to choose from. These documents are all deemed to have some relevance to the query produced by using an information retrieval algorithm. Thus far, automatic support has only been provided until the document retrieval level. The user is then left to search through the result set, mostly unaided, by the system he is using. In order to facilitate support for the users, a solid understanding of the information seeker's behaviours during this triage process is vital. Thus far, research into the behaviour of information seekers during the specific triage behaviour is limited. Even more limited however, is the evidence reporting the visual attention of the users. Since the triage process is highly visual, this important element needs to be thoroughly evidenced before accurately conceptualising the entire process. For this reason, this thesis aims to investigate the visual attention of information seekers during the document triage process. This will inform the modelling and conceptualisation of information seekers' behaviour during triage. In turn, this can be used to inform the design of supportive software. The thesis contains a review of related research and identifies the gaps that needs further investigation. From these, a series of user studies are then conducted on document triage. These in turn, facilitate the formulation and discussion of 2 document triage models and measurements to record the effectiveness of document triage. We study the visual attention of information seekers in four lab based studies, eliciting their exact gaze and focus details. We expand current research in the information seeking domain by reporting on findings from users' triage activities on small screen devices and when under time constraints. Furthermore, a high level diary study, gives us richer data on participants' triage activities over a larger period of time in their natural surroundings. All the studies are brought together to elicit requirements and measurements to understand system and user efficiency during each stage of the triage process.

Die zunehmende Bedeutung des Internets für die Veröffentlichung und Präsentation statistischer Daten stellt die amtliche Statistik vor neue Herausforderungen. Infolge des erleichterten Zugriffs auf die Angebote des Statistischen Landesamtes wächst die potentielle Nutzergruppe bei gleichzeitig zunehmender Differenzierung der verfolgten Nutzerinteressen und des bereits vorhandenen Vorwissens der Endkunden. Zielstellung des Amtes ist daher unter anderem die nutzerfreundliche und transparente Aufbereitung ausgewählter Datenbestände, um einen schnellen und einfachen Datenzugang zu ermöglichen. Ein dabei verfolgter Weg ist die Verwendung moderner Werkzeuge für die Darstellung von größeren Datenmengen, so dass erste strukturelle Zusammenhänge und relevante Eigenschaften der präsentierten Daten intuitiv erfasst werden können.

The rapid growth of touchscreen mobile devices has opened up many new opportunities for exploring Content-based Image Retrieval (CBIR) techniques, e.g., it has enabled the development of intuitive and natural user interfaces to facilitate the Query-by-Drawing (QbD) image search paradigm. Although ubiquitous mobile computing holds the promise of drastically changing the ways users search for images from large image repositories, there is yet no comprehensive and systematic study that examines the factors that influence the usability, user behaviours and task performance of a QbD image search mobile application (App). No guidelines and principles exist for designing fundamental user interface components such as the colour picker and little is known how its different designs affect system usability and task performance. Little research exists that examines how different user interface designs affect the ways users draw the queries and how users go about the search process for different types of tasks. The questions of whether or not it is possible or how well users can perform QbD image search by drawing from memory of previously-seen images are unexplored. An understanding of these questions is very important and useful in the development of effective and user-friendly systems for a QbD image search App on touchscreen mobile devices. This PhD project attempts to answer these questions and more by examining the factors that influence the usability and task performance of a QbD painting search mobile application. Starting with a comprehensive literature review and current mobile App review of various related fields, we first designed and implemented a Client-Server painting search mobile App based on an existing CBIR algorithm as the research platform for collecting empirical data; we then conducted a focus group study from whose findings we re-designed the user interfaces of our QbD App. An online survey about art preference was carried out, and we designed four comprehensive user studies and recruited a total of 123 participants to take part in the experiments. Both qualitative and quantitative measures are collected and analysed to discover the various factors that influence the usability and task performance of the interface designs of a QbD image search mobile App and the memory drawing over time. Finally, we made recommendations and suggestions on the design and implementation of various interface components of the QbD image search mobile App based on our findings. This thesis presents the following contributions summarised as: 1) We build a flexible platform that can be used for research in drawing-related fields, such as a new QbD technique or interface tests and psychological study. 2)We present a comprehensive and systematic review of the methods and techniques related to the investigation of QbD image search mobile App. 3) We propose a new way of categorising colour picker: ‘1D-1D-1D’, ‘1D-2D’, and ‘3D’ colour picker. 4) The rationales of choosing stimuli are proposed and a real-world painting database is built. 5) We also develop a variety of novel methodologies for experimental design, data collection and data analysis, and we formulated a new protocol for assessing drawing accuracy and search result. 6) We propose some colour picker design guidelines through a series of experiments and the analysis of comprehensive experimental data. 7) Although indeed memory decays over time, we found the participants are able to draw from the memory of a painting with simple compositional structure (6-7 colour blobs), even for the paintings viewed a month ago. And finally, 8) the experiments also provide valuable insights into how general users draw and modify a query, and judge the result relevance for different tasks on mobile phones, as well as search pattern and memorisation strategy, which also extend a scientific understanding of using current Query-by-Drawing techniques for real world image search.

The researcher investigated internet usage among students at the University of Nairobi using a quantitative case study method. A questionnaire-based survey was done among 381 students and face-to-face interviews were conducted with the university‟s library staff. The research findings indicate that the students' level of awareness about the internet services offered at the university was high. The students had good basic computer and internet skills; however, they lacked more advanced skills and this negatively affected their use of internet resources. The students used the internet for various purposes, including to study, teach and do research; to communicate; and for social interaction. The major recommendations of the study include providing formal internet training and adequate facilities; implementing a better, inclusive policy on internet use; and better co-ordinated university efforts. Free internet access should be made available to all the university students, if not all members of the university community. / Information Science / M.A. (Information Science)

The researcher investigated internet usage among students at the University of Nairobi using a quantitative case study method. A questionnaire-based survey was done among 381 students and face-to-face interviews were conducted with the university‟s library staff. The research findings indicate that the students' level of awareness about the internet services offered at the university was high. The students had good basic computer and internet skills; however, they lacked more advanced skills and this negatively affected their use of internet resources. The students used the internet for various purposes, including to study, teach and do research; to communicate; and for social interaction. The major recommendations of the study include providing formal internet training and adequate facilities; implementing a better, inclusive policy on internet use; and better co-ordinated university efforts. Free internet access should be made available to all the university students, if not all members of the university community. / Information Science / M.A. (Information Science)