Evaluating distributed cognitive resources for wayfinding in a desktop virtual environment.

As 3D interfaces, and in particular virtual environments, become increasingly realistic there is a need to investigate the location and configuration of information resources, as distributed in the humancomputer system, to support any required activities. It is important for the designer of 3D interfaces to be aware of information resource availability and distribution when considering issues such as cognitive load on the user. This paper explores how a model of distributed resources can support the design of alternative aids to virtual environment wayfinding with varying levels of cognitive load. The wayfinding aids have been implemented and evaluated in a desktop virtual environment

Are two pairs of eyes better than one? A comparison of concurrent think-aloud and co-participation methods in usability testing

This paper presents the results of a study that aimed to compare the traditional concurrent think-aloud protocol with the co-participation method to determine the benefit of adding an additional participant to the testing session. The two methods were compared through an evaluation of a library website, and their relative validity and utility were measured using four points of comparison: overall task performance, test participants’ experiences, quantity and quality of problems discovered, and the cost of employing each method. The results of the study show significant differences between the performances of the two types of testing methods. The co-participation method was evaluated more positively by users and led to the detection of a greater number of minor usability problems. This method, however, was found to require a greater investment of time and effort on the part of the evaluator in comparison to the classical method. This study found no difference between the methods in terms of task performance

Conceptual Design Model of Computerized Personal-Decision AID (ComPDA)

To date, the attentions given to the improvement of decision support at organizational level has been enormous. On the contrary, academic research in improving the performance of computerized decision aid (CDA) for personal decision is lacking, in which some are dated. Nowadays, the existence of CDA which handles personal decision is mushrooming and progressively getting attention from users. Despite that, users’ perceptions of the suitable decision strategy and technique for CDA have not been subjected to systematic investigation. Literature reviews also indicate that most users do not go for complex mathematical techniques despite the fact that these techniques are better at handling the risks and uncertainties in decisions. In fact, more often than not, the development process of CDAs does not seem to adhere to any conceptual and theoretical model. In view of that, this study aims to propose a conceptual design model for computerized personal-decision aid (ComPDA). The following objectives are outlined to support the general aim: (i) to identify appropriate decision strategy and technique for ComPDA, (ii) to incorporate identified strategy and technique in the construction of conceptual design model for ComPDA (iii) to validate the conceptual design model in different situations via prototyping method and (iv) to measure the users’ perceived helpfulness of the ComPDA prototypes. Participatory design method was implemented in order to achieve objective i and ii. The findings were incorporated into the construction of the conceptual design model of ComPDA. In achieving objective iii, the conceptual design model was validated in two different case studies via prototyping: A- choosing development methodology in mobile computing course (md-Matrix); and B- purchasing a mobile phone (ep-Matrix). In achieving objective iv, an instrument (named as Q-HELP) was developed to measure the helpfulness (HLP) of the prototypes. This study identified four relevant constructs pertinent to helpfulness; reliability (REL), decision making effort (EFF), confidence (CON), and decision awareness (AWR). Altogether, 122 respondents participated where 63 were from case study A and 59 from case study B. Eight hypotheses were formulated comprising testing for correlation between all the constructs in Q-HELP with helpfulness, testing the average time spent to make a selection with and without the proposed ComPDA and testing if the mean score of helpfulness of the proposed ComPDA is high. Paired Samples t Test, Pearson Correlation analyses and descriptive analyses were utilized to validate the hypotheses. The results show that: REL and HLP are significantly correlated, EFF and HLP are significantly correlated, CON and HLP are significantly correlated, AWR and HLP are significantly correlated, the use of md-Matrix and ep-Matrix significantly reduces the time spent to make selection, mean score of helpfulness of md-Matrix is fairly high and mean score of helpfulness of ep-Matrix is high. However, it is concluded that the overall results exhibit sufficient indication that md-Matrix and ep-Matrix were found helpful to users in terms of reliability, lessening the decision making effort, increasing confidence and also awareness in decision making. This study has produced the following outcomes, along with achieving all of its objectives: (i) a conceptual design model for ComPDA which incorporates suitable decision strategies and techniques identified via systematic investigations; (ii) two functional ComPDA prototypes to validate the conceptual design model and to demonstrate its applicability in different situations, (iii) an instrument for measuring helpfulness which includes dimensions from outcome and process aspects; and (iv) comparative analyses of decision models, strategies and techniques which provide basis for future studies.

From the web of data to a world of action

This is the author’s version of a work that was accepted for publication in Web Semantics: Science, Services and Agents on the World Wide Web. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Web Semantics: Science, Services and Agents on the World Wide Web 8.4 (2010): 10.1016/j.websem.2010.04.007This paper takes as its premise that the web is a place of action, not just information, and that the purpose of global data is to serve human needs. The paper presents several component technologies, which together work towards a vision where many small micro-applications can be threaded together using automated assistance to enable a unified and rich interaction. These technologies include data detector technology to enable any text to become a start point of semantic interaction; annotations for web-based services so that they can link data to potential actions; spreading activation over personal ontologies, to allow modelling of context; algorithms for automatically inferring 'typing' of web-form input data based on previous user inputs; and early work on inferring task structures from action traces. Some of these have already been integrated within an experimental web-based (extended) bookmarking tool, Snip!t, and a prototype desktop application On Time, and the paper discusses how the components could be more fully, yet more openly, linked in terms of both architecture and interaction. As well as contributing to the goal of an action and activity-focused web, the work also exposes a number of broader issues, theoretical, practical, social and economic, for the Semantic Web.Parts of this work were supported by the Information Society Technologies (IST) Program of the European Commission as part of the DELOS Network of Excellence on Digital Libraries (Contract G038- 507618). Thanks also to Emanuele Tracanna, Marco Piva, and Raffaele Giuliano for their work on On Time

Understanding the role of social norms in a web-based personalised, feedback intervention for alochol use

Excessive alcohol consumption in university students in the UK has been identified by Government agencies and health care providers as significant problem. Social norms research suggests students evaluate and regulate their own alcohol consumption through social comparison with peers. However, students are prone to misperceptions, inaccurately estimating others’ alcohol consumption to be higher than their own. The over estimation of normative peer alcohol consumption has been associated with higher personal alcohol consumption. Unitcheck is an online alcohol resource available to university students in the UK (www.unitcheck.co.uk). Using a social norms approach this online alcohol intervention provides instant personalised normative feedback to students, directly comparing reported individual alcohol consumption with normative peer alcohol consumption. This comparison is designed to correct students’ overestimation of normative peer drinking and encourage moderate alcohol consumption. Currently, Unitcheck feedback is labelled as comparing personal alcohol consumption to normative alcohol consumption of the typical University of Leeds student. There is a paucity of research exploring student responses to personalised normative feedback on an individual level. The aim of this study was to evaluate how students reporting alcohol consumption above recommended weekly limits at the University of Leeds, respond to instant, online personalised normative feedback presented as part of a study version of Unitcheck. A between subjects experimental design employing qualitative think-aloud methodology, plus a semi-structured interview was used. Participants were 21 Undergraduate students in their first or second year of study at the University of Leeds, 67% female, mean age 19.3 years (range 18-21), meanalcohol consumption over the previous week 38.4 units (range 10-150). Participants were randomised to one of two study groups and asked to work through the Unitcheck resource whilst thinking their thoughts aloud. Group A (n=11) used a same-sex referent group in the personalised normative feedback for University of Leeds students. Group B (n=10) used typical University of Leeds student as the normative referent group. All participants then completed a semi-structured interview assessing how believable and personally relevant they found the feedback. Findings from thematic analysis of the transcripts suggest that personalised feedback prompts participants to actively consider their personal value judgements regarding acceptable drinking behaviour. Students responded directly to the normative feedback component. Justifications of ratings of believability of normative feedback were based on personal observations of student drinking behaviour and perceived credibility of the normative data. The current manipulation focussed on gender as a salient comparison group, participants suggested year of study and age as alternative salient normative comparison groups

A Usability Approach to Improving the User Experience in Web Directories

Submitted for the degree of Doctor of Philosophy, Queen Mary, University of Londo

A usability approach to improving the user experience in web directories

PhDWeb 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

A Participative Approach for Objective and Subjective Evaluation of Seat Discomfort and User Interface Usability

The main aim of the work is the objective and subjective evaluation of two aspects of the interaction user-product, the seating discomfort and the user interface usability, relevant to industrial design, by using innovative methodologies for generating interpretative and predictive models that allowed the development of analysis strategies useful to improve the satisfaction of use of the types of industrial products considered. On the first aspect investigated, research in the field of medicine and epidemiology has shown that, over the past decades, the incidence of work-related musculoskeletal disorders (WMSDs) has considerably increased due to sedentary modern lifestyle, closely related to prolonged period of sitting. The importance of good office seating design in improving human wellness, greatly motivates the interest of specialized literature in topics related to the investigation of the biomechanical aspects of sitting and their effect on perceived discomfort. Typically discomfort assessment is realized on the basis of subjective evaluations and/or postural analysis by the interface pressures. In such context, the experimental sessions and the related data analysis were aimed to investigating on three critical aspects of seat discomfort assessment: 1) the relationship between subjective and objective measures of seat discomfort; 2) gender-based differences in seat interface pressure distribution; 3) discriminant effectiveness of indexes based on seat interface pressure. On the second aspect investigated, it's helpful to recognize that, today, design team can speed up the process of managing information related to design process by adopting digital pattern tools. These tools, as Knowledge Based Engineering (KBE) systems, can assist engineers in capture and re-use the multidisciplinary knowledge in an integrated way, in order to reduce time and cost of designing, to automate repetitive tasks and to support activities in conceptual design. The KBE analyzed in this study is a new digital pattern tool that supports the designers of automotive gearboxes. In such context, the research has focused on the evaluation of interface usability that represents a critical point in the development of a KBE system to demonstrate an effective reduction in the time and cost of designing and increased satisfaction in its use. The methods used for the two aspects studied are both theoretical and experimental and can be summarized in four main steps: 1) developmentofparticipativeprotocolsandexecutionofexperimentalsessionswith collecting of objective measures related to the interaction user-product and subjective measures related to user perceptions; 2) organization, classification and synthesis of experimental data collected by using techniques of descriptive statistics; 3) definition of interpretative and predictive models of phenomena investigated including by developing synthetic indexes, by using techniques of multivariate and multicriteria analysis; 4) statisticalvalidationofthesemodelsandindexes. The main results achieved concern the assessment of user-product interaction for different types of industrial products where such evaluation is essential. The outcomes are originals because they allowed to find the factors that had most influence on case studies and to develop synthetic indexes useful for identify some critical issues related use. Statistical data analysis provided new information relating to phenomena examined. Furthermore, the proposed data analysis strategies can be easily adapted to other experimental contexts, involving different target populations, and could have important effects in the industrial field, because they allow the reduction of design time (with obvious consequences on cost) and improvement of products in terms of end-user satisfaction