The fidelity of prototype and testing environment in usability tests

This doctoral thesis investigated what setup of a usability test can best support valid test outcomes. Several aspects of contextual fidelity were manipulated in experimental usability studies, to examine their impact on test results. The first study demonstrated that the medium of prototype presentation has effects on test outcomes, which have not been found in previous research. Using a more hypothesis-driven approach, it was shown that participants exhibited more reading activity when using a paper-based as compared to a computer prototype presented on screen. This resulted in better performance, if task success required reading a short paragraph of text. Consequently, the medium of prototype presentation needs to be considered to avoid that respective usability problems go undetected. A second study demonstrated that additional observers may cause stress for test participants, which can be measured at the physiological level. Some performance indicators were affected, but only in interaction with perceived developmental stage of the test system. A third study investigated the effects of a work or leisure context on the outcome of a usability test. No effects were found for the type of usage context, but even short response time delays proved to be relevant for performance and emotions. Relevant factors for the validity of usability test outcomes were identified and theoretical and practical implications are discussed. Keywords: Usability test; paper prototype; fidelity; observer presence; work and leisure domain; system response time; heart rate variability; validity

A collaborative design process for educational digital resources in African higher education

Within Africa, access to digital library systems is critical in supporting higher level teaching, learning and research. Currently there is a high demand with inadequate resources which often produces poorly supported learning outcomes. The effectiveness of current resources is further limited by poor design processes, which is worsened by stakeholders (academics, e-learning technologists and digital librarians and designers) often working in isolation. Ultimately, designed resources become less user-centred and sustainable. This thesis sought to provide empirically developed collaborative design process guidance for design stakeholders developing educational digital resources within African higher education. Following a Human Computer Interaction research approach, eleven best practice digital library projects identified from three case studies of African universities (in Kenya, Uganda and South Africa) were investigated. Data was drawn from interviews, observations and an examination of documents. This investigation identified three interrelated factors that impacted on the design process (i. e. human relationships, innovative technologies and policies). The human relationships factor comprised multidisciplinary design stakeholders and included a subset i. e. design champions (multidisciplinary and domain champions) whose role changed the facilitation and eventual output of the other stakeholders in the design process. The multidisciplinary champions took on a participatory approach to engagement while the domain champions assumed an approach that was less engaging. The innovative technologies factor comprised universal technologies and `flexible' technologies (i. e. Web 2.0 applications and the Open Source Software) which supported the design process and enhanced user-centeredness and sustainability of the projects. Existing institutional and national policies supported stakeholder collaboration and application of the innovative technologies. The absence of any of these factors in the digital library projects weakened the design process and reduced effectiveness of digital resources. These three factors have been used to develop the Collaborative Educational Resources Design (CERD) process model as a guidance tool to support multidisciplinary design stakeholders indesigning effective digital resources

The usability of knowledge based authentication methods on mobile devices

Mobile devices are providing ever increasing functionality to users, and the risks associated with applications storing personal details are high. Graphical authentication methods have been shown to provide better security in terms of password space than traditional approaches, as well as being more memorable. The usability of any system is important since an unusable system will often be avoided. This thesis aims to investigate graphical authentication methods based on recall, cued recall and recognition memory in terms of their usability and security

Literacy and ICT: Social Constructions in the Lives of Low-literate Youth in Ethiopia & Malawi

This thesis explores how literacy and Information and Communication Technologies (ICTs) are socially constructed in the lives of low-literate youth in the context of Ethiopia and Malawi. Literacy and ICTs are becoming more and more interdependent and both are seen as possible solutions for development. However, few studies have qualitatively explored the interaction between the two in contexts where literacy skills are not widespread, such as in Africa. Particularly the perspectives and experiences of low-literate users in such contexts have previously received insufficient attention. The thesis brings together and contributes to the social constructionist perspectives on literacy and ICTs, building in particular on the work of Brian Street and Daniel Wagner as well as Wiebe Bijker, Trevor Pinch and Paul Dourish, according to which literacy and ICT use are social practices that can only be understood in the social context in which they take place. In the context of four research locations in both urban and rural Ethiopia and Malawi, a qualitative multiple method approach (including interviews, focus groups and digital camera interaction) was employed, which allowed low-literate youth to express themselves both verbally and visually about the role of ICTs in their lives. What their realities reveal about how the use of ICTs is actively shaped by both its users as well as the context of use is organised in three substantive chapters. The first examines the interplay between literacy and ICTs, particularly with respect to language, content representation and shared use. This is followed by an exploration of physical and cultural contextual factors that constrain ICT use, such as electricity and gender. Finally, the needs of low-literate users as well as the way in which they shape ICT use according to their needs are explored. The thesis shows how the interplay between literacy and ICT use is more complex than just compatibility between literacy proficiency and ICT design. It highlights how ICT use is divided along similar lines to literacy proficiency by characteristics such as gender, language and geographical location. Furthermore, it shows how in an African context ICT design for collective rather than individual use may be more appropriate