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A novel quality assessment system design for closed captioning (CC) is proposed. CC was originally designed to serve hearing-impaired audiences. Traditional quality assessment models focus on empirical methods only, measuring quantitative accuracy by counting the number of word errors in the captions for a segment. However, hearing-impaired audiences have been outspoken about their dissatisfaction with the quality of current CC. One solution to this problem may involve inviting human evaluators, who represent different groups, to assess the quality of CC at the end of each segment, but in reality, this may be difficult to do and very labor-intensive. To solve this challenge, we propose the training and use of an artificial intelligence system to predict subjective CC quality based on human assessment data. In this paper, the design and development process, to be used in developing this system, is described .

There has been considerable research on design of menu hierarchies in general spanning several decades. However there is much less research on menus relating to specific types of product in online retail settings. Thus there is little guidance in the research literature on specific issues such as how to place luxury items within a beauty product hierarchy, which is the focus of this paper. We report on a study that addressed this problem for an ecommerce site associated with a large Canadian retailer. In a within subjects design, participants searched for four beauty-related products (two of which were classed as “luxury” items) either in a hierarchy where luxury items were intermingled with other products addressing the same need (the “Combined” condition), or in a hierarchy where there was a split between luxury and non-luxury products at the top level (the “Split” condition). Segregating luxury products in the product hierarchy was found to lead to significantly slower, and more lengthy (in terms of links traversed), searches. Searches were found to be more efficient in the “Combined” condition than the “Split” Condition both when searching for luxury items, and when searching for non-luxury items. This work has implications for existing brick-and-mortar retailers moving into or expanding e-commerce portals. Our results suggest that the separation of luxury from non-luxury items in bricks-and-mortar stores does not transfer well to online product hierarchies, where similar segregation leads to poorer digital navigation performance.

Closed Captioning (CC) is a service primarily designed for deaf and hard of hearing (D/HoH) viewers. The CC translates spoken speech into text for television or film screen display. The quality assessment methods for live captioning are limited to quantitative measures, while the viewers are still dissatisfied with the current quality. One method to improve the current quality assessment procedure is to include D/HoH viewers in the evaluation procedure for their subjective assessment input. However, it could be costly and impractical to perform evaluations for the entire broadcasted shows. Therefore, it would be helpful to model subjective assessments that could replicate and predict human decisions. In this article, we report on a model of probabilities of D/HoH viewer assessment decisions for CC quality factors based on actual user preferences. An online survey was designed and conducted to collect assessment data for 22 error variation samples from four quality factors: delay, speed, missing words, and paraphrasing of captions. The results are analyzed using the signal detection theory framework to create decision probability models for D/HoH viewers.

In this paper we explore how memories of experience with streaming video affect Quality of Experience (QoE) indicators that are of interest to service providers and marketers. Since observations of experience are time consuming, and the effects of technical quality (TQ) are difficult to entangle from content quality (CQ), we examined the impact of a visualization methodology for assessing experiences. A study was carried out to examine how well overall technical quality (TQ) judgments for a sequence of visualized video experience (a picture of a red video playbar with yellow portions indicating disrupted video in place of actually viewed video) would correspond to overall TQ judgments made after watching a sequence of actual videos. Sequencing effects found in overall TQ ratings, made after viewing visualizations (with their overlaid disruptions) were similar to sequencing effects found after viewing actual videos. However, the sequencing effects after viewing the visualizations were less pronounced than the corresponding sequencing effects that were found after viewing actual videos. Sequences of both visualized and actually viewed videos showed significant negative end effect and trend effects (both positive and negative). There was also evidence that sequencing effects respond to relative change in TQ rather than absolute TQ.

Objectives Recognition of delirium in the emergency department (ED) is poor. Our objectives were to assess: (1) the diagnostic accuracy of the Predicting Emergency department Delirium with an Interactive Computer Tablet (PrEDICT) "serious game" to identify older ED patients with delirium compared to clinical recognition and (2) the feasibility of the PrEDICT application compared to existing tests of attention. Design Prospective observational study. Setting ED of a Canadian tertiary care center. Participants We included ED patients, aged 70 years and older, with a minimum 4-hour stay. We excluded anyone with critical illness, communication barriers, and visual impairment or those unable to use a computer tablet. None had prevalent delirium by ED clinicians' routine clinical assessment. Measurements Participants were asked to tap targets on a tablet at four difficulty levels. Time and accuracy were automatically recorded. Other measures included the Confusion Assessment Method, the Delirium Severity Index, the Digit Vigilance Test (DVT), and the Choice Reaction Test (CRT). Results We enrolled 203 patients. Their average age was 80.6 years, 49.8% were female, and their average ED length of stay was 15.9 hours. Sixteen subjects had clinically unrecognized delirium, and 14 of them completed the PrEDICT game (87.5%). We developed a threshold score with 100% sensitivity (95% confidence interval [CI] = 76.8%-100.0%) and 59.7% specificity (95% CI = 52.3%-66.6%) to identify patients with clinically unrecognized delirium. The area under the curve was 0.86 (95% CI = 0.77-0.94). Completion rates were 196/203 (96.6%) for the PrEDICT serious game compared to 128/203 (63.1%) for the CRT and 51/203 (25.1%) for the DVT. Conclusion Older ED patients were able to use our serious game, including 87.5% of those with clinically unrecognized delirium. The PrEDICT application has potential to act as a sensitive screening tool to identify older ED patients with clinically unrecognized delirium. J Am Geriatr Soc 67:2370-2375, 2019.

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.

In this paper, individually reported long-term care (LTC) quality indicators have been supplemented with the composite Qindex measure and applied to 614 homes in Ontario, Canada. This study (1) describes the overall quality performance of LTC homes across five years (2012-2017) and (2) determines if organizational factors impact quality performance. The results demonstrate significant, continuous sector-wide improvement in overall quality performance (as assessed by the Qindex) over time and significant differences in quality based on home size, operator size and ownership. This paper positions the Qindex, a global metric of quality, as a valuable tool for quality measurement and management in the LTC sector.

Curved displays are believed to create a feeling of immersiveness similar to virtual reality. However systematic studies are needed to demonstrate that this is, in fact, true and under what conditions. In an experimental study 24 participants compared five different displays (concave, convex, hemisphere, sphere and a flat display) in terms of their immersiveness and perceptibility, and they also rated their overall preferences. Both immersiveness and perceptibility affected overall preference ratings. Participants gave higher preference ratings to the convex and concave displays, which were rated high in immersiveness and perceptibility, but gave lower preference ratings to the hemisphere/spherical display which had high ratings on immersiveness but low ratings on perceptibility. The study results imply that curved displays do indeed create a feeling of immersiveness. Concave and convex displays were rated highly favorably and should receive more attention for applications where visual experience and a feeling of immersiveness is particularly important.

This thesis introduces a new method to measure subjective ratings of technical quality (TQ) in disrupted video (DV). Current measurement methods are subject to extraneous factors such as delays introduced by the streaming software/hardware and the impact of video content. The proposed method is designed to supplement current methods by avoiding the confounding effects of content on TQ ratings and by reducing the time and effort necessary to run experiments. The new method replaces actual video with images representative of videos that contain various disruptions. In the research reported in this thesis, I ran an experiment with 37 participants to explore the viability of assessing TQ using visualizations instead of actual videos. The experiment compared ratings made after actually watching videos that varied in TQ versus ratings made after viewing the TQ visualizations, without actually seeing corresponding videos with associated impairments or failures. The results of the experiment showed that, with appropriate training, ratings of TQ made, after viewing the visualizations only, were similar to TQ ratings made after actually watching videos with corresponding impairments or failures.%%%%M.A.S.

The needs of vulnerable populations have been addressed, traditionally, by an ecosystem of private and public agencies that rely on donations (goods, money and services) which they re-distribute based on their perception of what is needed and where. This approach lacks a comprehensive understanding of the demand side as well as the ability to coordinate between various suppliers of goods and services, predict future demand and identify latent supply. We present a knowledge-based platform that utilizes advances in several Artificial Intelligence fields for a more efficient and effective way of provisioning goods and services to people in need.

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.

We conducted an experiment with 22 participants to investigate the effect of presentation style of a secondary task on a 1-D tracking task that simulated gap control in driving. Participants operated the tracking task with a foot pedal while performing a secondary task (counting vowels in a list of multiple letters) under conditions involving different modalities (audio/ visual), presentation styles (simultaneous/ sequential), task complexity (the number of distractors), and time dependency (list length). Our results showed that audio conditions with a longer and/or more complex secondary task did not improve primary (tracking) task performance, even though eye gaze dwelling time on the primary monitor in these cases tended to be substantially longer than the corresponding times in visual conditions. For a more complex version of the secondary task (longer list lengths) visual presentation of the task all at once (simultaneously) led to better performance then sequential presentation (whether visual or auditory). When given a choice people also tended to prefer simultaneous visual presentation of the secondary task. We discuss the effect of presentation modality of the secondary task in terms of its implications for user interface design in vehicles.

Customer satisfaction is an important factor governing adoption and retention of multimedia products and services, such as Over-The-Top(OTT) video transmission. Quality of Experience involves user-centric evaluation of various services. However, users differ in terms of their ratings of service quality. Some rating differences are due to unreliability (outlier users who are not motivated, or are not sensitive to differences in quality), but others are systematic differences in rating that may reflect different perspectives on quality. In this paper, we explore the use of outlier analysis and clustering as tools for interpreting QoE data. We report on experimental results demonstrating the use of outlier analysis and clustering. In interpreting the clusters, we examine users' opinions on different types of video disruption, and their ability to distinguish the different levels of impairments/failures.

The study reported in this paper demonstrated, for the first time, that the peak-end effect, commonly found with respect to memories of experience, also applies to overall Quality of Experience (QoE) measures obtained after participants view a sequence of videos. Sequences of videos shown in an experiment varied according to the sequencing and grouping of videos with better or worse Technical Quality (TQ). An end effect was found for both better TQ and worse TQ videos. However the peak effect was found for bad, but not good, videos. These results provide an important first step towards the development of models of Likelihood to Recommend (L2R) based on accumulated experience with a service.

In this paper, we study the relationships between Quality of Service (QoS) and Quality of Experience (QoE) in a session-based Over-The-Top (OTT) video service. A number of Performance Metrics (PMs) with and without the existence of failures during a video are examined. As QoE factors, Technical Quality (TQ) and Acceptability are used. We analyze the correlation between QoS performance metrics and QoE factors, and find new PMs should be employed because failures are included in QoE evaluation. We also summarize the relationships between QoS metrics and QoE factors through machine learning approaches. Using decision tree, we have a general idea about the relationships between PMs and QoE factors. We also understand the impact caused by failures and the value of rating scales.

Quality of Experience (QoE) is a crucial guiding factor for network management of an end-to-end service session. The network provider can control the resources allocated to sessions and in doing so, influence the Technical Quality (TQ), which covers the technical aspects of signal quality during the session. On the other hand, the network provider has no control over the Content Quality (CQ), which pertains to the user's level of interest in a particular video. Together TQ and CQ influence the Overall eXperience (OX) in a session. In this paper, we present results from a user subjective study in which the impact of TQ and CQ on OX was investigated for Over-The-Top (OTT) video sessions from the perspective of a network provider. This perspective places a focus on those elements of QoE that can be controlled by the provider. Various studies have shown that very high interest in a content can strongly influence QoE independent of other factors, so our study uses videos that are neutral with respect to content. We assess the TQ, CQ and OX for video sessions that contain Integrity impairments (in the form of image freezing) and failures in terms of session Accessibility and Retainability. Our findings indicate that TQ and CQ have a strong impact on OX in the presence of impairments, but no failures. On the other hand, TQ is the main determinant of OX when failures are present.

Memories of experience are influenced by a peak-end effect [13]. Memories are modified to emphasize the final portions of an experience, and the peak positive, or negative, portion of that experience. We examine peak-end effects on judged Technical Quality (TQ) of online video. In two studies, sequences of different types of video disruption were varied so as to manipulate the peak-end effect of the experiences. The first experiment demonstrated an end effect, plus a possible peak effect involving negative, but not positive, experience. The second study manipulated payment conditions so that some sessions were structured as requiring payment to watch the video. The second study also distinguished between a peak effect and a possible sequence effect. Evidence was again found for an end effect, with a secondary effect of sequence, but no evidence was found for a peak effect independent of sequencing.

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.

Consumer acceptance 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, impacting the acceptability of the product or service. Factors such as the Technical Quality (TQ) which covers the technical aspects of the signal quality can be controlled from the network provider. On the other hand, the network provider has no control on the subject's level of interest in a video, the Content Quality (CQ). Together TQ and CQ influence the Overall eXperience (OX) of the subject and, in the case of Over The Top (OTT) video, in a video session. In this paper, we present results from a user subjective study in which the impact of TQ and OX on the acceptability was investigated for OTT video sessions. To minimize the CQ impact on OX, the videos were carefully selected to have relatively neutral content. We assess the impact of TQ and OX on acceptability for videos containing impairment and failure events during lifecycle, thus affecting Accessibility, Retainability and Integrity. Our experimental results indicate that TQ and OX have a strong impact on acceptability.

The Evidence at the Point of Care (EPoCare) project (Takeshita, Davis, Straus, 2002) is examining how to put clinical evidence on mobile devices to meet physicians' information needs at the point of care. Forty-seven physicians, including family physicians, general internists and medical residents, participated in usability testing with prototypes implemented on two different form factors (a tablet-style PC and a PDA-style handheld). During the testing physicians were asked to describe their impression of the prototype and to indicate their agreement with 20 statements concerning the prototype implementations. The three user groups differed in how they valued device portability and screen size. Family physicians wanted larger screen size and were less concerned with portability, while internists wanted portability and were less concerned with screen size. Residents wanted both portability and large screen size. Cluster analysis was used to identify four clusters of physicians, varying by age, amount of time in clinical practice, and frequency of use of search engines and medical databases. Differences in preferences about format of information were present amongst these clusters. This study demonstrates how large sample usability testing can be used to develop customization strategies for mobile applications, for designing both form factor and content.

Measurement of video Quality of Experience is needed to enable telecommunication service operators to provide acceptable video viewing experience to their customers. Without accurate Quality of Experience measurement, it is hard to predict customer satisfaction. Accessibility and Retain ability failures are important factors that can affect the experience of viewing video on the Internet. Most of the published work in the assessment of Video Quality of Experience has focused on the quality of video viewing sessions without considering the impact of Accessibility and Retain ability failures. In this paper, we focus on the Quality of Experience for video sessions in the presence of Retain ability failures. We primarily evaluate video Quality of Experience for videos with temporary interruptions, called Integrity impairments, as well as with permanent interruptions called Retain ability failures. A subjective study was conducted to observe the effect of Retain ability failure on video Quality of Experience. The results of the subjective study suggest that videos with Retain ability failures are rated much lower than videos without any failure. An initial linear model for QoE of videos subject to Retain ability failures is introduced.

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.

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 conducted an experiment in order to investigate impacts of centralexecutive (CE) functions and modality of secondary task presentation in a dualtaskexperiment. We found that shifting ability, out of three major CE functions(inhibition, shifting, and updating) was particularly important in determiningwhether primary (pedal-tracking) task performance was better in the presence ofauditory, vs. visual, presentation of the secondary task.

Computers have become an important tool for participating in society for many people with disabilities. Recent efforts in rehabilitation engineering have focused on input techniques for the human-computer interface and on improving the visual presentation of information. However, as these visual presentations become more sophisticated, currently exemplified by Graphical User Interfaces (GUIs), access for people with visual or cognitive impairments often becomes more difncult. A model of feedback that is relatively independent of sensory modalities (i.e., visual, auditory and tactile) has been proposed by Fels, Shein, Chignell and Milner (1992) as a basis for designing user interfaces for people with a wide range of sensory abilities. One key component identified in this model is a standardised feedback vocabulary that describes screen elements. A study was conducted to determine whether target users could use the elements of this language to identify the elements within existing screens. Results indicate ...

We measured multitasking performance across a range of device interfaces and investigated the relationship between task performance and three measures of cognitive capacity (assessing the executive processes of shifting, inhibition, and updating, respectively). In the first experiment, higher levels of ability on the three executive processes of shifting, updating and inhibition were associated with improved multitasking performance. However, the impact of cognitive demands was reduced when touch input and combined visual and audio output was used in the device interaction task. When a simulated driving task was added in the second experiment, the impact of cognitive demands increased, and the use of combined audio and video output no longer reduced the impact of Central Executive (CE) function ability on performance.While inhibition, updating, and shifting all seemed to be involved when carrying out the device operation during simulated driving, the effects of shifting and updating ability were greater than the effect of inhibition. Detailed analysis of the data indicated that the impact of cognitive demand when using a device in a dual task setting was restricted to people with low levels of shifting, updating, and inhibition ability. It is suggested that future research on the impact of in-vehicle technology focus on drivers with low levels of ability on or more of a range of cognitive factors, including the CE functions of shifting, updating, and inhibition. Based on the present results it seems likely that less cognitively able drivers will be put at most risk by inappropriate or poorly designed device tasks and interfaces.

We are exploring how virtual reahty theories can be applied toward palmtop computers. In our prototype, called the Chameleon, a small 4-inch hand-held monitor acts as a palmtop computer with the capabihties of a Silicon graphics workstation. A 6D input device and a response button are attached to tbe small monitor to detect user gestures and input selections for issuing commands. An experiment was conducted to evaluate our design and to see how well depth could be perceived in the small screen compared to a large 21-inch screen, and the extent to which movement of the small display (in a palmtop virtual reality condition) could improve depth perception, Results show that with very little training, perception of depth in the palmtop virtual reality condition is about as good as corresponding depth perception in a large (but static) display. Variations to the initial design are also discussed, along with issues to be explored in future research, Our research suggests that palmtop virtual reality may support effective navigation and search and retrieval, in rich and portable information spaces.

Healthcare is a critical activity that consumes a high proportion of the wealth of societies. Governments and healthcare systems around the world are seeking to limit runaway healthcare costs while providing high quality services in ways that balance the competing needs of different groups of people. New technologies are providing opportunities to make healthcare more efficient and effective through better communications and access (e.g., Abraham et al., 2008). The increasing use of mobile devices in hospitals (Kuziemsky et al, 2005) is leading to new types of mobile application (e.g., Agarwal et al., 2007, Bardram and Bossen, 2005, Munoz et al., 2003).

Growing interest in emotional interfaces and systems motivates the need for a standard and well-accepted way to measure emotional responses. We introduce the concept of Emotional Majority Agreement: a metric to characterize affective self-report instruments. Emotional majority agreement scores describe the extent to which a sample of participants agrees with regards to their emotional responses. We present a video-watching case study where 12 participants continuously rated how they felt using three self-report prototypes. Majority agreement measures differentiated videos that elicited more or less agreement, prototypes that supported more or less agreement, and individual differences between participants. We conclude with insights gained and future work.

This workshop was part of a set of workshops that examined issues relating to the design and implementation of smart interaction. This workshop focused on smart interactions in healthcare contexts. Healthcare is a critical activity that consumes a high proportion of the wealth of societies. Governments and healthcare systems around the world are seeking to limit runaway healthcare costs while providing high quality services in ways that balance the competing needs of different groups of people.

Most discussions of hypertext usability are not founded in empirical measurement but more on conjectures based on personal experience. In this paper we report on two empirical analyses of hypertext usability, focusing on the quality of links produced by different means. We conducted two experiments to test the predicted relevance and the evaluated relevance of links, that is, where links are evaluated either before or after they are traversed. In order to evaluate these two kinds of relevance, we conducted two experiments where a hypertext document was created from a printed text. In each experiment we compared the relevances of three different sets of links. One set was created by a human author, whereas the second set was created automatically using the HEFTI (Hypertext Extraction From Text Incrementally) model for converting text into hypertext. We also generated a third set of links by assigning links randomly between nodes. The main goal of this research was to develop empirical tests that evaluate the usability of hypertext links. A second goal was to test the validity of automatically generated links using the HEFTI model. In this paper we detail the two experiments, and discuss their implication for methods of hypertext usability assessment and design.

Background To identify individual differences in physicians' needs for the presentation of evidence resources and preferences for mobile devices. Methods Within-groups analysis of responses to semi-structured interviews. Interviews consisted of using prototypes in response to task-based scenarios. The prototypes were implemented on two different form factors: a tablet style PC and a pocketPC. Participants were from three user groups: general internists, family physicians and medicine residents, and from two different settings: urban and semi-urban. Verbal protocol analysis, which consists of coding utterances, was conducted on the transcripts of the testing sessions. Statistical relationships were investigated between staff physicians' and residents' background variables, self-reported experiences with the interfaces, and verbal code frequencies. Results 47 physicians were recruited from general internal medicine, family practice clinics and a residency training program. The mean age of participants was 42.6 years. Physician specialty had a greater effect on device and information-presentation preferences than gender, age, setting or previous technical experience. Family physicians preferred the screen size of the tablet computer and were less concerned about its portability. Residents liked the screen size of the tablet, but preferred the portability of the pocketPC. Internists liked the portability of the pocketPC, but saw less advantage to the large screen of the tablet computer (F[2,44] = 4.94, p = .012). Conclusion Different types of physicians have different needs and preferences for evidence-based resources and handheld devices. This study shows how user testing can be incorporated into the process of design to inform group-based customization.

Medical doctors require high quality clinical evidence at the point of care in order to support their decision-making. Presentation of clinical evidence on handheld devices, and in a timely fashion, requires an integrated approach to documentation and ergonomic design. This paper reports on results from The Bringing Evidence to the Point of Care Project at the University of Toronto, concerning the display of quantitative data as part of clinical evidence. After introducing the problem and some of the relevant background literature, we indicate some prototype designs for presenting quantitative information on a handheld device, as graphs or tables. We then report on an initial usability study that compares the different prototypes. The results indicate that the doctors preferred statistical information to be presented as tables on the handheld device used in this study (in preference to lists or graphs).

Publisher Summary This chapter discusses the psychology of augmented human behavior. The evolution of human-computer interfaces and the implications of technological augmentation for the study of human psychology are discussed. Human capability and behavior are changing as more artifacts become part of the standard equipment that people carry around and use. This chapter reviews human–computer interaction and shows the way the constructive nature of perception and cognition may facilitate the implementation of augmenting technologies. Human–computer interaction is seen as a discipline that identifies principles and techniques for designing and evaluating user interfaces in human–computer systems. Attempts to model the psychology of human–computer interaction have generally led to a detailed analysis of tasks and to engineering models of human performance that focus on modeling of information processing activity in terms of response times. Psychology as a discipline is yet to describe the functions and properties of humans, per se, let alone the functions and properties of people interacting with complex technology.

In this paper we examine the reliability of subjective rating judgments along a single dimension, focusing on estimates of technical quality produced by integrity impairments and failures (non-accessibility, and non-retainability) associated with viewing video. There is often considerable variability, both within and between individuals, in subjective rating tasks. In the research reported here we consider different approaches to screening out unreliable participants. We review available alternatives, including a method developed by the ITU, a method based on screening outliers, a method based on strength of correlations with an assumed “natural” ordering of impairments, and a clustering technique that makes no assumptions about the data. We report on an experiment that assesses subjective quality of experience associated with impairments and failures of online video. We then assess the reliability of the results using a correlation method and a clustering method, both of which give similar results. Since the clustering method utilized here makes fewer assumptions about the data, it may be a useful supplement to existing techniques for assessing reliability of participants when making subjective evaluations of the technical quality of videos.

Sequential (vs. simultaneous) presentation of two letters in a physical-identity matching task enhanced the fast-same effect, but did not reduce the preponderance of false-“different” errors or the effect of visual similarity. Thus, the sequential enhancement of the fast-same effect involves an increased efficiency in encoding (d’) owing to letter repetition, as Proctor claimed, rather than a criterion shift (β), and it involves the visual code rather than the name code. The increased efficiency in detecting sameness with sequential presentation might result from spatial separation (e.g., reduced lateral interference and self-termination), though, rather than temporal separation (e.g., priming), However, such spatial factors as letter size and interletter spacing had no consistent effect on the speed advantage forsame pairs, and it was concluded that temporal, not spatial, separation enhances the fast-same effect on sequential trials, Consistent with the response-competition model (Eriksen, O’Hara, & Eriksen), responses were slower and more errorful to similar than to dissimilardifferent pairs, and were equally fast to dissimilar andsame pairs on simultaneous trials.

Video mediated communication alters our perception of the way in which we interact and communicate. In contrast to face to face or audio only (e.g., telephone) communication, there is relatively little systematic research on the effect of video conferencing on communication within groups of people at dispersed locations (Harrison, 1991b; Harrison et al, 1992b; Sellen, 1992; Wolf, 1988; Cohen, 1982; Short, Williams, and Christie, 1976). In this paper we describe a study of how participants at three distant locations perceived differences between face to face (within site) and video mediated (between site) communication. Results indicate that participants perceived between site, mediated communication to be unnatural and uncomfortable. They felt there were problems with gaining floor control and with conversation flow. Additionally, participants perceived the between site, mediated communication to be less interactive, less social, and less enjoyable than the face to face, within site communication. The insights gained through this and other case studies, summarized here, will be used to guide our future research. This study is one in a series of field trials and controlled experiments aimed at understanding the human factors issues associated with video communication and the design of such systems.

Searching audio data can potentially be facilitated by the use of automatic speech recognition (ASR) technology to generate text transcripts which can then be easily queried. However, since current ASR technology cannot reliably generate 100% accurate transcripts, additional techniques for fluid browsing and searching of the audio itself are required. We explore the impact of transcripts of various qualities, dichotic presentation, and time-compression on an audio search task. Results show that dichotic presentation and reasonably accurate transcripts can assist in the search process, but suggest that time-compression and low accuracy transcripts should be used carefully.

In replicating a national survey dealing with political attitudes in the New Zealand population (2) the authors had to consider the problems associated with classifying their own newly obtained sample of 451 individuals in terms of the responses elicited by an interview which included 35 attitude items and nine biographical measures. The attitude items were designed to measure responses to the political situation and New Zealand society in general, while the biographical measures were sex, age, marital starus, time spent in employment, number of children, educational qualifications, occupation, source of income, and political affiliations. The three responses allowed for each attitude item were (a) agree, (b) 'uncertain, and (c) disagree. Data were analysed using automatic interaction detection analysis (3) after an alternative clustering method (requiring considerable computational expense) did not uncover any structure in the dam (1). The 35 attitude items were used as the independent variables, with political affiliation being the marker (dependent) variable on which the splitting process was based. Separate analyses were run on rwo nonoverlapping subsets of the data (250 cases and 201 cases). Three clusters were identified as common to both analyses. People in cluster one were generally happy and satisfied with NZ politicians. People in cluster two were dissatisfied with NZ politicians but found politics boring. Those in cluster three were unhappy wich NZ politicians but found politics interesting. A stepwise discriminant analysis was then used, with the 26 son-political attitude responses as the independent variables, to identify non-political attitude differences between the three clusters. The remaining attitude which distinguished between the clusters was the belief that New Zealanders care about one another. Only 23% of cluster one disagreed with the statement that New Zealanders care about one another (the rest either agreed or were uncertain) while 53% and 45% of clusters two and three, respectively, disagreed with the statement. Political affiliation indicated that cluster one corresponded roughly to the right end of the political continuum while cluster three was at the lefr end. Members of cluster rwo divided their support over four political parties. A detailed description of the survey results are available from the authors.