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Quality of Experience (QoE) is a measure of the overall level of customer satisfaction with a vendor. In telecommunications, consumer satisfaction is of great interest in the adoption of novel multimedia products and services. A number of factors can greatly influence the customer experience during a video session. Factors such as user perception, experience, and expectations are expressed by QoE while factors such as application and network performance are expressed by Quality of Service (QoS) parameters. This paper studies the relationship between QoS and QoE in a session-based mobile video streaming. Specific QoS Application Performance Metrics (APMs) are examined based on a QoE assessment database which is built for experimentation and contains 108 subjects. It is shown that these APMs are highly related to two QoE factors, Technical Quality (TQ) and Acceptability. Furthermore, Viewing Ration (VR) parameter and the corresponding Kendall correlation between VR and QoE factors proves that VR is a valuable metric for mapping QoS to QoE. We further generated the compacted decision tree to predict QoE factors through Rebuffering Ratio (RR), Non-interruption Content Viewing Ratio (VRc), and Non-interruption Viewing Ratio (VRs). Through extensive experimentation, a general relationship between APMs and QoE factors has been examined and a primary QoE model is proposed based on this relationship.

This study measured Session Quality of Experience (SQE) by letting people look at visual proxies of a video play bar without having to watch the actual video, with its associated impairments and/or failures. We supplemented a laboratory study of 10 participants with two further online samples of 14, and 20, participants respectively, obtained using online surveys. Cluster analysis was carried out on the entire data set of 44 participants and clusters were obtained representing differences in sensitivity to pricing and to types of disruption. Crucially, there was no significant dependency between samples and cluster demonstrating that visualization can be used in a crowdsourcing, as well as a laboratory, context. This study demonstrates the combined use of crowdsourcing, visualizations of service experience, and cluster analysis to create more efficient, and nuanced, interpretations of SQE.

Technology questionnaires can assist in developing profiles that characterize the ability of people to use new technologies. Technology profiles may also be related to physical and cognitive abilities, and may possibly serve as proxies for constructs that may be more difficult to measure. The purpose of the research reported in this paper was to examine possible relationships between responses to questions about use of technologies and functional and frailty status as measured using a digital, tablet-based test battery. A battery of digitized cognitive and functional assessments was administered on a tablet, along with a technology questionnaire, to Canadian adults over 65 years who called 911 for paramedic services or who presented to an emergency department. 330 people between the ages of 65 and 97 years (mean = 75.8 years, standard deviation = 7.6) participated in the study. We observed significant relationships between elderly adults’ responses to questions about their technology use and their functional status and frailty scores with more technology use implying better functional status and less frailty. It is suggested that the present findings may lead to the use of more detailed technology profiles as efficient proxy estimates of overall functional ability and frailty status in elderly adults.

Walking and cognitive function are interrelated, and thus normal control of gait is perturbed by cognitive impairment. Changes in gait, as measured by quantitative analysis, can be a useful mechanism for detecting early indicators of cognitive decline. Observing changes in gait in the dual-task paradigm, i.e. when the subject walks while performing an attention-demanding task, can be a more sensitive measure. In the study reported in this paper, we developed a mobile application to perform quantitative gait assessment in the single and dual-task condition, using a smartphone’s built in sensor system. We show that the gait parameters, as measured by a mobile device, are significantly related to the corresponding parameters reported by a gold-standard motion capture system. We also demonstrate that this approach may be comparable to previously validated assessments of cognition and executive functioning. Mobile technologies offer a platform for sensitive assessment of changes in cognitive function through gait analysis in dual-task conditions. This methodology opens the way for more frequent assessments of cognition, as part of physiotherapy and rehabilitation practice.

Results of an empirical study on the privacy concerns, attitudes, and behaviour of personal health record (PHR) users are presented. The study addressed the following questions: (1) What are the factors influencing privacy concerns of PHR users? (2) To what extent do PHR users read privacy agreements and which factors are in play when they fail to read them. (3) Are the behaviour and attitudes of PHR users consistent with respect to reading privacy agreements and using privacy settings? We infer from the study results that the factors influencing privacy concerns of general online users (as reported in literature) also apply to PHR users. In spite of privacy concerns, 60% of the respondents in our study reported not reading privacy agreements. PHR users who were highly concerned about privacy did not report changing their default privacy settings (as offered in a typical social networking website) in a manner consistent with their stated attitudes towards privacy. Based on the issues identified in the study we conclude with a number of design recommendations for privacy-friendly PHR systems.

Requirements analysis defines the goals and evaluation criteria of system design. We introduce a methodology for requirements analysis for customization based on large sample interactive testing, with the premise that analysis of user behaviour with prototypes leads to requirements discoveries. The methodology uses a relatively large sample (1) to identify relevant user subgroups, (2) to observe significant empirically determined group differences in the context of task and tool use and (3) to estimate the groups’ different requirements and derive design implications. Between 20 and 50 participants are used per test, rather than the three to five often recommended for user testing. Statistical relationships are investigated between subgroups in terms of background variables, questionnaire items, performance data, and coded verbal statements. Customization requirements are inferred from the significant differences observed between empirically determined groups. The methodological framework is illustrated in a case study involving the use of clinical resources on handheld devices by three groups of physicians. The groups were found to have different needs and preferences for evidence-based resources and device form factor, implying opportunities and necessities for group customization requirements. Relevance to industry In safety-critical domains such as health care, it is essential to assess user needs and preferences regarding devices and systems to inform appropriate customizations. We present a methodological framework and case study that demonstrates how large sample user testing can supplement typical methods of requirements analysis to provide contextualized, quantitative accounts of group differences and customization requirements.

The rapid development of blogs as a social networking tool has greatly increased the number of people who are expressing themselves in text published online. As yet little is known about the social psychology of online interaction using recently developed Web 2.0 functionalities. To what extent do principles of social psychology carry over into the online domain and how can appropriate use of those principles assist in activities such as community building, e-commerce, marketing, and personalization of services? There would seem to be a large number of novel research questions that can be posed with respect to online interaction. One pertinent question concerns the extent to which compatibility of personality influences online interaction. We investigated this question in terms of hypotheses derived from the personality research literature, using a two-part experiment. In the first study, eight participants wrote blogs in two distinct genres (personal diaries and commentaries) and rated their own personalities. In the second study 12 different participants judged the personality of authors as implied in the blog texts created in the first study. Those participants also completed a personality questionnaire and rated their attraction to the blog text author. Readers of the blog corpus were able to consistently judge the personality of the writers based solely on the text that they wrote. Moreover, they followed a well-established social rule regarding interpersonal attraction in real-life interaction. Blog readers were significantly more attracted to blog writers with more similar personalities-offering support that in a blog environment, ''birds of a feather flock together.'' Emotion word use in the blog corpus correlated with writer's personality, suggesting that online personality may be signalled by linguistic cues. The two most popular genres of blog writing, personal journal and commentary, differed in how accurately readers judged author personality traits. Based on the results obtained it is suggested that personality is an important determinant and that further research on how people communicate with blogs will be relevant to social network analysis and to marketing.

This paper describes a study of content and communication processes in multidisciplinary meetings of healthcare professionals, using a Human Factors engineering approach. The goal of the study, which took place in a teaching hospital Toronto, Canada, was to understand the processes of collaboration and information exchange that take place in the meetings, and to identify potential supports for the meetings, including the use of information technology. The methodology included data collection through observation of the multidisciplinary patient care meetings, and quantitative analysis of verbal exchanges in those meetings. The results suggested the need for a standardized approach to information exchange using structured language.

The results from a series of three experiments that used Text Retrieval Conference (TREC) data and TREC search topics are compared. These experiments each involved three novel user interfaces (one per experiment). User interfaces that made it easier for users to view text were found to improve recall in all three experiments. A distinction was found between a cluster of subjects (a majority of whom were search experts) who tended to read fewer documents more carefully (readers, or exclusives) and subjects who skimmed through more documents without reading them as carefully (skimmers, or inclusives). Skimmers were found to have significantly better recall overall. A major outcome from our experiments at TREC and with the TREC data, is that hypertext interfaces to information retrieval (IR) tasks tend to increase recall. Our interpretation of this pattern of results across the three experiments is that increased interaction with the text (more pages viewed) generally improves recall. Findings from one of the experiments indicated that viewing a greater diversity of text on a single screen (i.e., not just more text per se, but more articles available at once) may also improve recall. In an experiment where a traditional (type-in) query interface was contrasted with a condition where queries were marked up on the text, the improvement in recall due to viewing more text was more pronounced with search novices. Our results demonstrate that markup and hypertext interfaces to text retrieval systems can benefit recall and can also benefit novices. The challenge now will be to find modified versions of hypertext interfaces that can improve precision, as well as recall and that can work with users who prefer to use different types of search strategy or have different types of training and experience.

There was a proliferation of electronic information sources and search engines in the 1990s. Many of these information sources became available through the ubiquitous interface of the Web browser. Diverse information sources became accessible to information professionals and casual end users alike. Much of the information was also hyperlinked, so that information could be explored by browsing as well as searching. While vast amounts of information were now just a few keystrokes and mouseclicks away, as the choices multiplied, so did the complexity of choosing where and how to look for the electronic information. Much of the complexity in information exploration at the turn of the twenty-first century arose because there was no common cataloguing and control system across the various electronic information sources. In addition, the many search engines available diAered widely in terms of their domain coverage, query methods and eAciency. Meta-search engines were developed to improve search performance by querying multiple search engines at once. In principle, meta-search engines could greatly simplify the search for electronic information by selecting a subset of first-level search engines and digital libraries to submit a query to based on the characteristics of the user, the query/topic, and the search strategy. This selection would be guided by diagnostic knowledge about which of the first-level search engines works best under what circumstances. Programmatic research is required to develop this diagnostic knowledge about first-level search engine performance. This paper introduces an evaluative framework for this type of research and illustrates its use in two experiments. The experimental results obtained are used to characterize some properties of leading search engines (as of 1998). Significant interactions were observed between search engine and two other factors (time of day and Web domain). These findings supplement those of earlier studies, providing preliminary information about the complex relationship between search engine functionality and performance in diAerent contexts. While the specific results obtained represent a time-dependent Information Processing and Management 35 (1999) 337‐362

The newspaper represents a mature information presentation medium that is well-suited to the display of relatively short, loosely related pieces of text. This work examines the implementation of the newspaper metaphor in an information exploration interface. Based on an analysis of differences between electronic books and electronic newspapers, we submit that the newspaper metaphor is an appropriate interface paradigm for large-scale full-text databases. Similarities between newspapers and hypertext databases lead us to suggest that this metaphor is appropriate for large automatically generated hypertexts, independent of the nature of their content. We describe VOIR, a software prototype that we have used as an electronic newspaper workbench. The program constructs newspaper pages interactively, and allows users to specify their information-seeking intent in a variety of ways, including graphical Boolean queries, hypertext links, and typed-in queries. We report some empirical evidence that indicates that users perform better when they are shown more articles simultaneously. These results suggest that the newspaper metaphor may be an effective organizing principle for a class of information exploration tasks. Finally, we discuss some implications that this work has for hypertext and information retrieval in general.

We describe a method to derive design models for hypermedia interfaces from the bottom up. Firstly, we compile a list of hypermedia interface features which we classify according to the category of functions they fulfill. We then describe an experiment in which candidate designs for low-level interface features were designed and tested for recognizability. In the experiment, icons for each of 61 hypermedia concepts were generated and then judged. Finally, we outline and illustrate a model induction phase in which low-level features are combined into an overall interface model, via "micro-models" that take account of the types of icons that worked best for each class of interface feature. We suggest that, at least for hypermedia systems, a bottom-up approach to interface design based on the functions of low-level features is preferable to the dominant, top-down approach based around one or more metaphors.

Background Asthma action plans improve asthma outcomes and are recommended in guidelines. However, delivery by physicians and usage by patients remain low. This may be because of variability in existing plans and a failure to consider visual design and usability factors in plan development. Objective To characterize the variability in both the content and the format of existing plans, and the extent to which their format conforms to evidence-based visual design recommendations. Methods We collected plans from the internet, Canadian experts and associations, guidelines, and published trials. We inductively developed analytic criteria for format and content analyses. Results We collected 69 unique English or French-language adult outpatient plans from around the world. We found large variability in format, and plans fulfilled a mean of only 3.5 out of 8 evidence-based visual design recommendations. Content was also variable, including different descriptions of the baseline clinical state and descriptions and instructions at each “action point” (point recommending a change in treatment). Conclusion Existing plans vary widely in content and format. Accordingly, studies evaluating the effectiveness of action plans may not be directly comparable. Also, visual design may affect usability, uptake, and effectiveness. Our results suggest that this has not been adequately addressed in most plans, and design evidence and experts should be included in future development.

The requirements of maintaining supervisory control of a complex system may sometimes exceed the capability of the human operator for a variety of reasons ranging from temporary distraction from the main task to excessive mental workload. The ergonomic aspect of complex supervisory control can be improved by augmenting the interface with expert systems. This paper outlines the development of an intelligent warning system as one component of an augmented supervisory control system for complex aircraft. The system is designed to alert the pilot to potentially hazardous conditions during instrument landing approaches. The process of task analysis that precedes the implementation of the system is outlined, drawing on the experience of a former military pilot. The results and methods shown here can be generalized to other components of the pilot's task and, more generally, to other complex supervisory control tasks.

Chignell, M.H., Loewenthal, A. and Caspi, A., 1986. The principles of caveat vendor, caveat emptor, and caveat operator in robotic safety. Journal of Occupational Accidents , 8: 79–90. The issue of robotic safety in semi-automated manufacturing environments is considered, using human factors, case study, and accident prevention/liability approaches. The roles of the manufacturer, owner and operator of the robot in ensuring safe operation of robots are examined. General safety guidelines for robotic operation in semi-automated environments are given, but it is recognized that the complexity and variety of human-robot—machine systems necessitates that more rigid and detailed safety standards be set on a case by case basis.

Despite the promise and prominence of artificial intelligence, successful widely-based applications have been rare. Much of previous artificial intelligence work has concentrated on the demonstration of techniques rather than the development of tools that can be used in systems design, analysis and operation. A systematic program of knowledge compilation in artificial intelligence is proposed where extensible function libraries can be used by professionals in various fields and non-programming specialists in developing artificial intelligence applications.