The aim of this thesis is to incorporate the results of Experientialism in the domain of Human-Computer Interaction. The purpose is twofold: on the one hand it shows how some concepts of Experientialism like metaphor, image-schema, stories or conceptual integration may be used to explain where some concepts of HCI come from. On the other hand it uses the same conceptual background to support the design activity: the same concepts of Experientialism may be employed to build new conceptual artifacts in order to design User Interfaces and application software in general. One of the most fruitful ideas Experientislim may offer is conceptual integration as the basis upon which to construct new design solutions. Notwithstanding the pervasive use of metaphor in everyday language and even in HCI texts, there is a considerable amount of criticism regarding the use of metaphor in designing user interfaces based on the assumption that this practice may be the origin of troubles when using such software products. That is why one of the chapters is aimed at showing that not only the use of metaphor is pervasive in HCI but even the use of figurative language as well. Not only figurative language is usually employed but it is even one of the main tools for conceptualising new ideas and concepts required in the activity of software development. The Thesis proposes a framework aimed at designing User Interfaces based on the concepts of Experientialism. The proposal integrates two phases (analysis and design) the same way as most of software development methods do, trying to profit on the broad scope of the cognitive processes such as image-schema, metaphor and conceptual integration. These general concepts may be well suited to build conceptual models upon which to elaborate the user interfaces and the optirnalizy principles proposed to study the suitability of conceptual integration may be also used as validity criteria to evaluate such design artifacts. In order to validate such a proposal, the Thesis shows how to use the framework in two different situations: i) to explain why a problem such as the Mac trashcan -used to eject diskettes- is not a problem of using metaphors but an unfortunate design decision, and ii) to be applied in the design of a new User Interface. Other concepts of Experientialism are proposed in capturing user requirements. The concept of story is the ground on which to build scenarios or use cases, as stories are a more general cognitive process and a form of telling things at a more general level. That is why the user stories may be mapped to use cases, as both are essentially different type of stories and the capture of requirements is a way of specifying one type of stories (use cases) based on the original stories (user stories).

This thesis explores the acquisition of spatial knowledge as a means to support wayfinding in virtual environments. Specifically, the thesis presents an investigation into the potential benefits one might gain through the application of a variety of tools, each of which has been designed to support one of the three stages of cognitive map development - landmark-based representation, route-based representation, and survey-based representation (Siegel & White, 1975). Each tool has been evaluated with respect to improvements in wayfinding, and also in their support for environmental learning. Measures were taken of each tool used in isolation, and also when used together as a complete toolset. The between-subjects evaluation process involved 101 participants, randomly assigned to one of five conditions. Each participant was asked to navigate a virtual environment to locate three specific items. To evaluate wayfinding, participants were asked to perform the same task on six occasions within the same session. After discovering all items, a measure indicating route efficiency was recorded. On completing all six trials participants were asked to produce a map of the virtual environment. It was hypothesised that the presence of tools would improve the acquisition of spatial knowledge, and thus route efficiency and map production. Comparing the 'no-tool' and the 'all tool' conditions, a 2x6 repeated measures ANOVA found that when providing the tools concurrently there was a statistically significant improvement in the efficiency of route taken (F(1,38)=4.63, p<0.05). However, when evaluating the tools in isolation, no significant improvement in route efficiency was found. Also, no significant difference between conditions was identified when comparing the quality of maps produced by participants across conditions. The thesis concludes by arguing that the application of the complete toolset benefits wayfinding, although it is noted that the evidence does not support the hypothesis that this is caused by improved spatial learning.

This thesis explores the gap between theory and practice within the context of humancomputer interaction (HCI), specifically relating to effective implementation of HCI methods and frameworks within practice. The thesis is structured as follows: three connected but stand-alone papers are presented preceded by an introduction, and followed by a conclusion. The introduction defines HCI, discusses its history and evolution, and how it has been influenced by different disciplines. The first paper covers the usability of personalisation of Web sites and consists of three quantitative studies. The main measurements are effciency, effectiveness, and satisfaction as indicators of usability. Two of the studies show a significant relationship between the amount of content on a page and time taken to find information. The third study shows that when users are only allowed 3-5 seconds to glance through the page (skim), the significance, found in the other two studies, disappeared. There is, however, no indication that subjective satisfaction is affected, regardless of the amount of time users take to find information in any of the studies. The second paper is a case study: a practical evaluation of how usability is implemented in commercial website design projects. It compares the difference between targeting usability issues early in the design and later in the development. The third paper conceptualises involving users early on in design projects, how this affects design projects in the context of Garrett's (2002) framework and how it compares with current and optimal approaches. It shows that involving users early in the design process does not negatively affect time or effort and concludes by defining areas where research should concentrate to provide further evidence towards involving stakeholders in Web design through researchable propositions. Finally, the conclusion chapter summarises each of the paper's limitations and conclusions. It links the three papers through a discussion on how they are related in addition to how this research could benefit the practitioner

A range of resources exist to support overweight and obese personnel with their weight management efforts in the Royal Navy (RN). However, the high prevalence of personnel with excess weight in the RN suggests that these resources may be insufficient. Web-based weight loss interventions may be particularly well-suited for addressing the problem of overweight and obesity in the RN, as they may provide flexible and easily accessible support that can be accessed in users’ own time. This thesis presents an evaluation of the first web-based weight loss intervention for overweight and obese RN personnel. A systematic review and meta-synthesis of 17 studies was conducted to explore overweight and obese adults’ perceptions and experiences of behavioural weight management interventions. The review indicated several factors that overweight and obese people perceived as affecting their weight management efforts, which if addressed, could improve the credibility of weight management interventions. A survey study with 1030 RN personnel identified there was some interest in using a web-based weight loss intervention in the RN, particularly among obese personnel and female personnel. A qualitative study with 21 overweight and obese RN personnel identified participants’ perceived barriers and facilitators within the Naval environment that were related to their weight management efforts. These findings were used to inform modifications to an existing web-based weight loss intervention. A second qualitative study explored 14 overweight and obese personnel’s perceptions and experiences of using the modified web-based weight loss intervention. Further modifications to the intervention were undertaken in light of the results from this study. A final feasibility study aimed to evaluate the possibility of trialling and implementing the modified web-based weight loss intervention among 43 overweight and obese RN personnel according to the Reach, Efficacy, Adoption, Implementation and Maintenance (RE-AIM) framework. It was estimated that the uptake of the intervention was 6% and it had a moderate effect on weight loss among users, despite not being implemented as intended. This thesis identified a number of suggestions for improving overweight and obese RN personnel’s engagement with web-based weight management interventions. These include the need for interventions to promote autonomous motivation among overweight and obese personnel to manage their weight, and interventions at the organisational level to change perceptions around weight management in the RN.