Usability Testing of Interactive Multimedia Services

Interactive mu ltimedia services, such as video-on-demand offered to the public at home need to be tested carefully for usability. The environment as well as users is heterogeneous and they use different input and output devices than with a personal computer. User Interface designers need to learn more about the users, their environment and the hindrances they encounter. Two service trials were conducted where thirty families had access to video-on-demand, news-on-demand and worldwide web services for three months. The users had access to the services via a set-top-box connected to a television or via a personal computer. The paper describes how three methods: logging, thinking-aloud and questionnaires were applied as well as their results. Finally, the experiences from using the methods are discussed

Knee arthroplasties performed at Akureyri University Hospital in the

Hægt er að lesa greinina í heild sinni með því að smella á hlekkinn View/OpenOBJECTIVE: Osteoarthrosis (OA) is a growing medical problem in western societies and the cost of the treatment has grown accordingly in the last years. Patients with OA often need to be operated on with arthroplasties and one important outcome measure for this type of surgery is the revision rate. The purpose of this study was to assess the results of knee arthroplasties performed at Akureyri University Hospital during 1983-2003, with special emphasis on revision rates, infections and other complications. MATERIAL AND METHODS: Information was gathered from journals of the 457 patients who underwent knee arthroplasties during 1983-2003. Information about the operation and hospital stay was recorded as well as if patients later became the subject of revision. CRR (cumulative revision rate) uses survival statistics to estimate the risk of revision after primary operation and was calculated for patients with OA operated on with knee arthroplasty. Statistical informations were calculated in Microsoft Excel. Kaplan Mayer analysis was used to calculate the CRR and that was done in SPSS 11.5. RESULTS: 560 primary operations were performed during the period, 515 total knee arthroplasties and 45 unicompartmental. 200 operations were performed on males and 360 on females. Mean ages for males was 70.8 years and for females 69.4 years. Revision rates varied depending on the type of implant. Twelve unicompartmental and 28 total knee arthroplasties became subject of revision. The PCA unicompartmental prosthesis most frequently needed revision, or in over 50% of cases. The CRR for the AGC total knee prosthesis was the lowest or around 3% at seven years, including revisions due to infections. Revisions due to infections were three in the period or 0.6% of all the total knee arthroplasties. Complications that substantially increase the risk of revision and/or are life-threatening were recorded in 1.8% of the operations at the time of discharge. Only one patient had pulmonary embolism (0.2%) and two patients (0.4%) had deep venous thrombosis. CONCLUSION: Our high revision rate for the PCA implant is consistent with what has been seen in other studies. This prosthesis was found to have mechanical problems and was withdrawn from the market. Our revision rate for the AGC implant as well as the rate of infections are low and the results are quite comparable to what has been found in Sweden by the Swedish Knee Arthroplasty Registry. The results of knee arthroplasties performed at Akureyri University Hospital, regarding revision rates, infections and complications, are fully comparable to other known results internationally.Tilgangur: Slitgigt er vaxandi vandamál í hinum vestræna heimi og kostnaður heilbrigðiskerfisins og samfélagsins vegna hennar farið vaxandi á undanförnum árum. Sjúklingar með slitgigt þurfa oft á gerviliðaaðgerðum að halda og því er mikilvægt að gera sér grein fyrir hversu vel tekst til með aðgerðirnar. Tilgangur þessarar rannsóknar er að kanna hver árangur af gerviliðaaðgerðum á hnjám hefur verið á Fjórðungssjúkrahúsinu á Akureyri á tímabilinu 1983-2003, með áherslu á tíðni enduraðgerða, sýkinga og fylgikvilla. Efniviður og aðferðir: Upplýsingar voru fengnar úr sjúkraskrám þeirra sem gengust undir gerviliðaaðgerð á hné á tímabilinu 1983-2003. Skráðar voru persónuupplýsingar sjúklinga og helstu upplýsingar um aðgerð, legu og útskrift. Eins var farið að með enduraðgerðir sem sjúklingar gengust undir. CRR (cumulative revision rate) var reiknað út fyrir sjúklinga sem höfðu gengist undir gerviliðaaðgerð vegna slitgigtar í hné. Tölfræðilegar upplýsingar voru unnar í Microsoft® Excel®. Beitt var Kaplan Mayer aðferðarfræði við útreikninga á CRR og var það gert í SPSS® 11,5. Niðurstöður: 560 frumaðgerðir voru gerðar á tímabilinu, 515 með heilliðum og 45 með hálfliðum. 200 aðgerðir voru gerðar á körlum og var meðalaldur þeirra 70,8 ár. 360 aðgerðir voru gerðar á konum og meðalaldur þeirra var 69,4 ár. Enduraðgerðir á hálfliðum voru 12 á tímabilinu og á heilliðum 28. Enduraðgerðartíðni var hæst á PCA hálfliðnum eða rúmlega 50% af öllum þeim PCA liðum sem settir höfðu verið inn. Cumulative revision rate (CRR) á AGC heilliðnum var lægst, eða um 3% við sjö ára uppgjör, að enduraðgerðum vegna sýkinga meðtöldum. Enduraðgerðir á heilliðum vegna sýkinga voru þrjár á öllu tímabilinu eða í 0,6% þeirra heilliða sem settir voru inn. Fylgikvillar sem auka verulega líkur á enduraðgerð og/eða eru lífshótandi eða valda alvarlegum líkamlegum einkennum komu fram í 1,8 % tilvika fyrir útskrift. Einu sinni var um að ræða blóðsegarek til lungna (0,2%) og í tveimur tilvikum fengu sjúklingar blóðtappa í neðri útlim (0,4%). Ályktun: Árangur af gerviliðaaðgerðunum í hnjám á FSA, hvað varðar enduraðgerðartíðni, sýkingar og fylgikvilla stenst fyllilega alþjóðlegan samanburð og eru góður kostur í meðferð slitgigtar hjá vel völdum sjúklingahópi

Identifying and explicating knowledge on method transfer: a sectoral system of innovation approach

Post-print (lokagerð höfundar)With the advances in information technology and its increasing impact on humans and society, there has been an expanding need to spread knowledge from domain to domain. This need is not least in the area of human–computer interaction, which includes a rich culture of carrying out usability evaluations in many different domains and technology platforms. This paper aims to show how transfer of methods takes place, by explicating and formalizing the process. It will contribute to the quest for knowledge on the constituents of the process of transferring methodological knowledge and their relationships. A sectoral system of innovation approach is used to analyse the constituents of a selected sector, crisis management, where training is essential and which is rapidly adopting technology for operations and training. Two case studies are described where heuristics evaluation and user testing were applied on simulation software that allows training for crisis management. The analysis results in a process model, describing the transfer of methodological knowledge within the sectoral system of innovation framework.The research leading to these results has received funding from COST Action IC0904, Twintide, and the European Union Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. [FP7-242474], CRISIPeer Reviewe

Heuristic evaluation: Comparing ways of finding and reporting usability problems

Research on heuristic evaluation in recent years has focused on improving its effectiveness and efficiency with respect to user testing. The aim of this paper is to refine a research agenda for comparing and contrasting evaluation methods. To reach this goal, a framework is presented to evaluate the effectiveness of different types of support for structured usability problem reporting. This paper reports on an empirical study of this framework that compares two sets of heuristics, Nielsen's heuristics and the cognitive principles of Gerhardt-Powals, and two media of reporting a usability problem, i.e. either using a web tool or paper. The study found that there were no significant differences between any of the four groups in effectiveness, efficiency and inter-evaluator reliability. A more significant contribution of this research is that the framework used for the experiments proved successful and should be reusable by other researchers because of its thorough structur

Transferability of Voice Communication in Games to Virtual Teams Training for Crisis Management

Publisher's version (útgefin grein)A crisis is an emergency event that can lead to multiple injuries and damage to property or environment. Proper training of crisis management personnel is vital for reducing the impact of a major incident. In search for knowledge on how best to implement communication for virtual environments for training, communication in online games was studied. Findings on voice communication in online games were researched and formulated as a set of statements. By asking participants in an empirical study of crisis management, the statements were either confirmed or refuted. Results show that multiplayer games are highly similar to the requirements for crisis management training in virtual environments. Approximately two-thirds of the statements proved coherent in both domains. The practical significance of this work lies in the provision of design implications for a virtual environment for crisis management training. Thus, this paper contributes to demonstrating the transferability between these domains. Finally, the paper reflects the results in theories of communication and engagement.Peer Reviewe

An analysis of a plane crash training event after action reviews

This report represents an analysis of an AAR (After Action) report from a practical training event that included AAR reports from nominated participants and AAR focus group meeting minutes. AAR reports are reviews of the outcome of a practical training event including positive and negative assertions regarding structure, quality and coordination besides proposals for improvements. The purpose of this analysis was to understand better the training process and the need for crisis management improvements. Furthermore, the purpose was to analyse how AARs could be attractive tools for crisis response improvements.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP/2007‐2013) under grant agreement no. [FP7‐242474]

Key Human-Centered Transition Issues for Future Oceanic Air Traffic Control Systems

Communication, navigation, surveillance, and decision support capabilities in Oceanic air traffic control are evolving significantly. It is important to consider the effect of the changes on the controller’s task. In this paper the results from multi-disciplinary studies performed at MIT (Massachusetts Institute of Technology) and the University of Iceland are presented. At MIT, a human-centered systems analysis was used to identify key human factors issues for the future Oceanic air traffic control environment to be experimentally investigated. At the University of Iceland, a prototype for a future air traffic control display was designed and evaluated. Both studies identified three key human factors issues that require consideration. The first is a mismatch between time and space separation restrictions imposed and information support provided, requiring the controller to cognitively resolve temporal/spatial mismatches to meet restrictions. The second issue is the effects of mixed communication and surveillance equipage, which complicates the control task and requires the controller to cognitively integrate asynchronous information. The final is the importance of cultivating controller trust and understanding issues of complacency and automation disuse when implementing highly automated conflict probes that are being considered in the future Oceanic environments

Haptic cues as a utility to perceive and recognise geometry

Publisher's version (útgefin grein)Research has been conducted on how to aid blind peoples’ perceptions and cognition of scientific data and, specifically, on how to strengthen their background in mathematics as a means of accomplishing this goal. In search of alternate modes to vision, researchers and practitioners have studied the opportunities of haptics alone and in combination with other modes, such as audio. What is already known, and has motivated research in this area, is that touch and vision might form a common brain representation that is shared between the visual and haptic modalities and through haptics learning is active rather than passive. In spite of extensive research on haptics in the areas of psychology and neuropsychology, recent advances and rare experiences in using haptic technology have not caused a transfer from basic knowledge in the area of haptics to learning applications and practical guidelines on how to develop such applications. Thus motivated, this study investigates different haptic effects, such as free space, magnetic effects and the bounded box when blind people are given the task of recognising and manipulating classes of 3D objects with which they have varying familiarity. In parallel, this study investigates the applicability of Sjöström’s guidelines on haptic applications development and uses his problem classification to capture knowledge from the experiments. The results of this study show that users can easily recognise and manipulate familiar objects, albeit with some assistance. There is an indication that users completed tasks faster and needed less assistance with magnetic effects. However, they were not as satisfied with this mode. While the results of this study show that haptics have the potential to allow students to conceptualise 3D objects, much more work is needed to exploit this technology to the fullest. Objects with higher complexity are difficult for students, and, in their opinion, the virtual objects (as presented) leave much room for improvement. Sjöström’s error taxonomy proved useful, and four of five sub-guidelines tested were confirmed to be useful in this study.Peer Reviewe

Novice evaluators' behavior when consolidating usability problems individually or collaboratively

Publisher's version (útgefin grein)An important, but resource demanding step in analyzing observations from usability evaluations is to consolidate usability problems (UPs) that were identified by several evaluators into one master list. An open question is whether consolidating UPs in pairs is cost-effective. A within-subject study examined if evaluators merge UPs differently when working in pairs than individually and what motivates their decisions. Eight novice evaluators took part. The number of discarded, retained and merged UPs, evaluators' confidence and severity of UPs in the two settings were measured. The results showed that UPs merged or discarded in the collaborative setting would rather be retained in the individual setting. Participants increased confidence and UP severity in the collaborative setting but decreased UP severity and confidence in the individual setting.Peer Reviewe

Argumentation Models for Usability Problem Analysis in Individual and Collaborative Settings

Post-print (lokagerð höfunda)Consolidating usability problems (UPs) from problem lists from several users can be a cognitively demanding task for evaluators. It has been suggested that collaboration between evaluators can help this process. In an attempt to learn how evaluators make decisions in this process, the authors studied what justification evaluators give for extracting UPs and their consolidation when working both individually and collaboratively. An experiment with eight novice usability evaluators was carried out where they extracted UPs and consolidated them individually and then collaboratively. The data were analyzed by using conventional content analysis and by creating argumentation models according to the Toulmin model. The results showed that during UP, extraction novice usability evaluators could put forward warrants leading to clear claims when probed but seldom added qualifiers or rebuttals. Novice usability evaluators could identify predefined criteria for a UP when probed and this could be acknowledged as a backing to warrants. In the individual settings, novice evaluators had difficulty in presenting claims and warrants for their decisions on consolidation. Although further study is needed, the results of the study indicated that collaborating pairs had a tendency to argue slightly better than individuals. Through the experiment novice evaluators’ reasoning patterns during problem extraction and consolidation as well as during their assessment of severity and confidence could be identified.Peer Reviewe