This paper describes two studies that examine the ways in which parameters of touch can be manipulated to support human–mobile interaction, providing designers with greater awareness regarding the range of tactile icons (tactons) for integration with interfaces. The first study examined the efficacy of presenting tactons via low-cost eccentric rotating motor vibration technologies, often used in the design of wearable interfaces. Findings highlight the role of intensity in supporting tactile recognition as well as the impact of duration, interval, and intensity on task time. In our second study, we build on these results by comparing the impact of simulated and real-world auditory distractors on the perception of four parameter tactons. Findings indicate the negative effects of realistic ambient sounds on recognition accuracy, time taken and cognitive workload, but the results also indicate that some tactile designs (e.g. those encoded with stronger intensities) better resist the effects of these auditory distractions. Our research suggests that mobile devices should be evaluated under real-world scenarios to ensure that tactile feedback presented via a mobile device meets the needs of mobile users.

Although it is well known that interaction with a mobile device can be impacted when the environment is inhospitable or when the user is on the move, situationally-induced impairments and disabilities (SIIDs) are often overlooked in the mobile interface design process. In this paper, we describe one step toward supporting mobile users with SIIDs, through the design of tactile notifications. The tactile channel offers considerable promise to convey notifications to the user, freeing their visual and auditory channels for other tasks. A study was conducted to determine whether participants could develop tactile cues to convey the key characteristics of alerts to mobile users (e.g. urgency, relationship with the sender). The results highlight the benefits of tactile prototyping tools to encourage generation of design ideas, and the use of scenarios to situate these design ideas within the intended context of use.

The need to study representative users is widely accepted within the human-computer interaction (HCI) community. While exceptions exist, and alternative populations are sometimes studied, virtually any introduction to the process of designing user interfaces will discuss the importance of understanding the intended users as well as the significant impact individual differences can have on how effectively individuals can use various technologies. HCI researchers are expected to provide relevant demographics regarding study participants as well as information about experience using similar technologies. Yet, in the field of accessibility we continue to see studies that do not appropriately include representative users. Highlighting ways to remedy this multifaceted problem, we argue that expectations regarding how accessibility research is conducted and reported must be raised if this field is to have the desired impact with regard to inclusive design, the information technologies studied, and the lives of the individuals being studied.

Older adults are recommended to remain physically active to reduce the risk of chronic diseases and to maintain psychological well-being. At the same time, research also suggests that levels of fitness can be raised among this group. This paper describes the development and evaluation of a mobile technology, which enables older adults to monitor and modify their walking habits, with the long-term aim of sustaining appropriate levels of physical activity. An empirical study was conducted with twenty older adults to determine the feasibility of the proposed solution, with results indicating that tactile signals could be perceived while in motion and could support participants in walking at a range of paces. However, the effects were difficult to discern due to limitations of the hardware. In response, a novel low-cost prototype was developed to amplify vibrations, and effectiveness of redundant auditory information was investigated with the goal of enhancing the perception of the cues. A second study was conducted to determine the impact of multimodal feedback on walking behavior. Findings revealed that participants were able to maintain a desired level of pace more consistently when redundant auditory information was presented alongside the tactile feedback. When the visual channel is not available, these results suggest that tactile cues presented via a mobile device should be augmented with auditory feedback. Our research also suggests that mobile devices could be made more effective for alternative applications if they are designed to allow for stronger tactile feedback.

The lack of quantifiable, reliable and repeatable methods for assessing functional capabilities of users with physical limitations creates challenges for accessibility researchers and practitioners. Current practice includes descriptors such as medical diagnoses, third-party observations, and self-assessment to characterize physical capabilities of information technology users. These solutions are inadequate due to similarities in functional capabilities between diagnoses, differences in capabilities within a diagnosis, and the potential for bias when characterizing functional capabilities. The current research examines performance-based functional assessment as an alternative to existing assessment techniques. Initial study results based on a single focus model (task efficiency) were reported earlier [1, 2]. This paper builds on that work, highlighting the benefits of integrating multiple perspectives such that both efficiency and anomalies are considered. A decision tree was produced combining results from several performance-based functional assessment models providing improved predictive capabilities.

The development of assistive technologies and ubiquitous computing highlights the need to better understand errors associated with both the limitations of the devices being used and difficulties introduced by the environment in which interactions occur. At the same time, we need to better understand the relationship between the user experience and the consequences users encounter when errors occur. Although error rates are the most common measure of reliability reported in the human–computer interaction literature, this simple metric fails to address the different consequences users may experience. We propose a new metric, leveraging the concepts of entropy and desirability, to quantify the concept of reliability. An empirical study provides a preliminary validation of this new metric, focusing on its ability to describe several aspects of user satisfaction as well as task completion time. Results confirm that our new metric is more effective than error rates when describing user satisfaction and that the metric can also be used to describe task completion times when error rates are high.

Although speech recognition has improved significantly in recent years, its adoption continues to be limited, in part, by the effort and frustration associated with correcting speech recognition errors. Error detection is a particularly challenging issue in third-party error correction where different individuals are responsible for the original dictation and correcting the resulting text. This research aims to address the difficulty experienced in third-party error detection by developing and evaluating a variety of support mechanisms. Drawing on a growing body of literature on human computer interaction and speech recognition, four support mechanisms were designed and evaluated, namely indexed audio, speech summarization, error prediction, and the presentation of alternative hypotheses. A user study assessed the impact of these support mechanisms on both performance and perceptions during error detection tasks. Performance measures included effectiveness and efficiency, and perception measures included confidence, perceived usefulness, and cognitive workload. The results provide strong support for the use of indexed audio in the context of third-party error detection. The results also confirm that consecutive error rate, or the percentage of recognition errors immediately adjacent to another error, has a negative impact on the effectiveness of third-party error detection. Other support mechanisms failed to improve either effectiveness or perceptions, but they did negate the negative impact as consecutive error rate increased. These findings have significant implications for speech recognition error detection research and the design of error detection support solutions.

This paper describes a study designed to identify salient tactile cues which can be integrated with a cellular telephone interface, to provide non-visual feedback to users when accessing mobile applications. A set of tactile icons (tactons) have been developed by manipulating the pulse duration and interval of vibrotactile signals. Participants were presented with pairs of tactons, and asked to differentiate between each respective pair and rank their salience. Results suggested that the combination of two static tactons is the most effective way to convey tactile information, when compared with dynamic or mixed tactile cues. Further studies will be conducted to refine feedback in order to communicate the presence of graphical objects on a mobile device interface, or to present events and alerts more effectively. The long term goal is to improve access to an interface by using the tactile channel, thereby freeing the visual and auditory channels to perform other tasks.

Speech recognition is a promising alternative input technology for individuals with upper-body motor impairments that hinder the use of the standard keyboard and mouse. A recent long-term field study found that the users employed speech techniques for a variety of tasks beyond generating text documents [1]. One challenge with hands-free speech-based interactions is user authentication, which requires the users to speak their user IDs and passwords character by character. Unfortunately, speaking a password presents both security and privacy threats as well as usability problems. To address this challenge, we propose a new speech-based authentication model. An initial proof-of-concept prototype has been implemented and a pilot study was conducted. Preliminary results suggest several problems for further examination.

Speech text entry can be problematic during ideal dictation conditions, but difficulties are magnified when external conditions deteriorate. Motion during speech is an extraordinary condition that might have detrimental effects on automatic speech recognition. This research examined speech text entry while mobile. Speech enrollment profiles were created by participants in both a seated and walking environment. Dictation tasks were also completed in both the seated and walking conditions. Although results from an earlier study suggested that completing the enrollment process under more challenging conditions may lead to improved recognition accuracy under both challenging and less challenging conditions, the current study provided contradictory results. A detailed review of error rates confirmed that some participants minimized errors by enrolling under more challenging conditions while others benefited by enrolling under less challenging conditions. Still others minimized errors when different enrollment models were used under the opposing condition. Leveraging these insights, we developed a decision model to minimize recognition error rates regardless of the conditions experienced while completing dictation tasks. When applying the model to existing data, error rates were reduced significantly but additional research is necessary to effectively validate the proposed solution.

Mobile information technologies are theoretically well-suited to digitally accomodate informal note-taking, with the notes often recorded quickly and under less than ideal circumstances. Unfortunately, user adoption of mobile support for informal note-taking has been hindered in large part by slow text entry techniques. Building on research confirming people's ability to recognize erroneous text, this study explores two simple modifications to Graffiti-based text entry with the goal of increasing text entry speed: disabling text correction and disabling visual feedback. As expected, both modifications improved text entry speed at the cost of recognizability. To address the decrease in recognizability, a multiapproach text-enhancement algorithm is introduced with the goal of modifying the erroneous note to facilitate the process of recalling the event or activity that originally motivated the note. A study with 75 participants confirmed that the proposed approach of discouraging user-initiated error correction during note-taking, enhancing the resulting erroneous notes, and facilitating recall with enhanced alternative lists, increased note-taking speed by 47% with no negative impact on the participants' ability to recall important details about the scenarios which prompted the note-taking activities. This research highlighs the importance and efficacy of shifting the focus from accuracy to recallability when examining the overall efficacy of informal notes. The proposed modifications and adaptations produce significant benefits and have important implications for how mobile technologies are designed to support both informal note-taking and text entry in general.

Existing knowledge on how people use speech-based technologies in realistic settings is limited. We are conducting a longitudinal field study, spanning six months, to investigate how users with no physical impairments and users with upper body physical impairments use speech technologies when interacting with computers in their home environment. Digital data logs, time diaries, and interviews are being used to record the types of applications used, frequency of use of each application, and difficulties experienced as well as subjective data regarding the usage experience. While confirming many expectations, initial results have provided several unexpected insights including a preference to use speech for navigation instead of dictation tasks, and the use of speech technology for programming and games.

The description of users with motor limitations is a significant dilemma for accessibility researchers and system designers alike. Current practice is to use descriptors such as medical diagnoses to represent a person's physical capabilities. This solution is not adequate due to similarities in functional capabilities between diagnoses as well as differences in capabilities within a diagnosis. An alternative is user self-reporting or observation by another person. These solutions are also problematic because they rely on individual interpretation of capabilities. The current research focuses on defining an objective, quantitative and repeatable methodology for assessing a person's physical capabilities in relation to use of computer technology. Results from this initial study are encouraging, including the development of a model which accounts for up to 85% of the variance in user capabilities.

Three National Science Foundation (NSF) programs—Human–Computer Interaction, Universal Access, and Digital Society and Technologies—were recently combined into one new cluster called “Human-Centered Computing” (HCC). Two workshops were held to share information about this new cluster with researchers, provide guidance to researchers who are early in their research careers and have yet to receive NSF funding, and provide feedback to NSF from the affected research communities regarding topics that are considered particularly important by this community. Continuing and emerging research opportunities identified included privacy and security issues in HCC context, intelligent user interfaces, universal access including research for different populations such as children and older adults, mobile and ubiquitous computing, and social computing, among others. Various issues concerning interdisciplinary research opportunities were also raised, including understanding the disciplines, promotion and tenure concerns, administrative overhead, and where to publish. Education discussions produced a list of curricular recommendations and a number of opportunities to enhance the education of future HCC practitioners and researchers.

Increased use of mobile phones and associated services in China highlights the need for effective Chinese input methods for mobile devices. Mapping thousands of characters to a standard telephone keypad is a significant challenge. Structure-based methods provide an appealing known-character/known-code solution, but assigning multiple strokes to each key forces users to learn new, often unfamiliar, mappings. Using an established stroke input method, our study revealed important effects of keypad legend on performance. Novice user performance was evaluated with several alternative keypad designs. The results confirmed that both abstract symbols and concrete examples helped improve the usability of the keypad in Chinese text-entry tasks. Further, combining abstract symbols and concrete examples resulted in performance nearly tripling as compared to the original design. The stroke-to-key mapping accuracy also increased significantly. Handwriting analysis confirmed that the reduced errors are directly associated with the keypad-based text-entry technique.

introduction Share on Introduction to special issue on computers and accessibility Authors: Andrew Sears UMBC, Baltimore, MD UMBC, Baltimore, MDView Profile , Vicki L. Hanson IBM T. J. Watson Research Center, Hawthrone, NY IBM T. J. Watson Research Center, Hawthrone, NYView Profile , Brad Myers Carnegie Mellon University, Pittsburgh, PA Carnegie Mellon University, Pittsburgh, PAView Profile Authors Info & Claims ACM Transactions on Computer-Human InteractionVolume 14Issue 3September 2007 pp 11–eshttps://doi.org/10.1145/1279700.1279701Published:01 September 2007Publication History 1citation810DownloadsMetricsTotal Citations1Total Downloads810Last 12 Months5Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my Alerts New Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access

Computer and Information Technologies have redesigned the way modern society operates. In particular, they have identified new avenues to provide tools and resources to alleviate the traditional ba...

As handheld devices become ubiquitous and the tasks performed become multipurpose in nature, efficient data entry techniques are necessary. This research evaluated several speech-based text entry solutions for handheld devices using server-based speech recognition. Because server-based solutions introduce network delays, an analysis of the relationship among network delays, number of recognition errors, how fast users can correct errors, and overall data entry rates was performed. The analysis and empirical results confirm the importance of minimizing recognition errors. This suggests that a server-based approach that makes more computing resources available may prove effective. Results from two empirical studies are presented. The first compares two error correction mechanisms: a multitap and soft keyboard solution. The second employs a longitudinal investigation of the effects of experience on text entry rates. Users attained an effective mean text entry rate as high as 25.3 words per min, which is higher than or comparable to data entry rates reported for other input techniques for handheld devices. The results of this research have implications for researchers and designers of automatic speech recognition systems and mobile devices.

Interest in context-aware computing has expanded the use of sensing technologies. The accelerometer is one of the most widely used sensors for capturing context because it is small, inexpensive, lightweight, and self-operable. In efforts to obtain behavioral patterns, many studies have reported the use of multiple accelerometers attached to the human body. However, this is difficult to implement in real-life situations and may not fully address the context of user interaction. In contrast, the present study employed a single tri-axial accelerometer attached to a handheld computing device instead of to a user. The objective was to determine what contextual information could be obtained from this more feasible, albeit limited, source of acceleration data. Data analyses confirmed that changes in both mobility and lighting conditions induced statistically significant differences in the output of the accelerometer. Categories and Subject Descriptors H.5.2 [User Interfaces]: Interaction styles (e.g., commands, menus, forms, direct manipulation)

Speech recognition can be a powerful tool for use in human – computer interaction, especially in situations where the user's hands are unavailable or otherwise engaged. Researchers have confirmed that existing mechanisms for speech-based cursor control are both slow and error prone. To address this, we evaluated two variations of a novel grid-based cursor controlled via speech recognition. One provides users with nine cursors that can be used to specify the desired location while the second, more traditional solution, provides a single cursor. Our results confirmed a speed/accuracy trade-off with a nine-cursor variant allowing for faster task completion times while the one-cursor version resulted in reduced error rates. Our solutions eliminated the effect of distance, and dramatically reduced the importance of target size as compared to previous speech-based cursor control mechanisms. The results are explored through a predictive model and comparisons with results from earlier studies.

The papers in this special issue of Behaviour & Information Technology represent state-of-the-art research in the area of Accessible Computing. Topics range from accessible computing solutions for ...

Speech recognition technology continues to improve, but users still experience significant difficulty using the software to create and edit documents. The reported composition speed using speech software is only between 8 and 15 words per minute [Proc CHI 99 (1999) 568; Universal Access Inform Soc 1 (2001) 4], much lower than people’s normal speaking speed of 125–150 words per minute. What causes the huge gap between natural speaking and composing using speech recognition? Is it possible to narrow the gap and make speech recognition more promising to users? In this paper we discuss users’ learning processes and the difficulties they experience as related to continuous dictation tasks using state of the art Automatic Speech Recognition (ASR) software. Detailed data was collected for the first time on various aspects of the three activities involved in document composition tasks: dictation, navigation, and correction. The results indicate that navigation and error correction accounted for big chunk of the dictation task during the early stages of interaction. As users gained more experience, they became more efficient at dictation, navigation and error correction. However, the major improvements in productivity were due to dictation quality and the usage of navigation commands. These results provide insights regarding the factors that cause the gap between user expectation with speech recognition software and the reality of use, and how those factors changed with experience. Specific advice is given to researchers as to the most critical issues that must be addressed.

The increasing popularity of Short Message Services (SMS) in China highlights the need for effective and efficient methods for entering Chinese text on mobile phones. While stroke-based methods have potential advantages over pronunciation-based solutions, usability issues have limited the effectiveness of existing stroke-based methods. One significant usability challenge has been the ambiguous stroke-to-key mapping rules that are typically employed. We proposed a new solution that employs a combination of abstract symbols and example strokes to help users map strokes to keys more effectively. A longitudinal experiment was used to evaluate character entry performance using both objective and subjective measures for our new design as well as the existing solution. The results confirmed that a new design allows for improved performance as well as higher satisfaction levels as compared to the original design. Further, after approximately 1 h of experience with the stroke-based method, novices were able to enter Chinese text at speeds comparable to that observed with the pronunciation-based Pinyin method. Results showed that the new design provided users with a better understanding of the system throughout the study, beginning with their first exposure to the keypad. By utilizing a combination of abstract representations and concrete examples of the available strokes, the new design reduced the ambiguity that typically exists regarding stroke-to-key mappings. In this way, usability was improved without any changes to the underlying technologies. Our results demonstrate that stroke-based solutions for Chinese character entry can be effective alternatives for mobile phones, providing an effective alternative for the many individuals who can write Chinese but do not speak the Mandarin dialect that serves as the basis for Pinyin. The improved solution could also be used with a traditional numeric keypad to allow one-handed data entry for desktop or mobile computers.

The efficiency promised by a dictation speech recognition (DSR) system is lessened by the need for correcting recognition errors. Error detection is the precursor of error correction. Developing effective techniques for error detection can thus lead to improved error correction. Current research on error detection has focused mainly on transcription and/or domain-specific speech. Error detection in DSR has been studied less. We propose data mining models for detecting errors in DSR. Instead of relying on internal parameters from DSR systems, we propose a loosely coupled approach to error detection based on features extracted from the DSR output. The features mainly came from two sources: confidence scores and linguistics parsing. Link grammar was innovatively applied to error detection. Three data mining techniques, including Na/spl inodot//spl uml/ve Bayes, neural networks, and Support Vector Machines (SVMs), were evaluated on 5M DSR corpora. The experimental results showed that significant performance was achieved in that F-measures for error detection ranged from 55.3% to 62.5%. This study provided insights into the merit of different data-mining techniques and different types of features in error detection.

Speech recognition can be a powerful tool for use in human-computer interaction. Many researchers are investigating the use of speech recognition systems for dictation-based activities, resulting in dramatic improvements in recent years. However, this same experimentation has confirmed that recognition errors and the delays inherent with speech recognition result in unacceptably long task completion times and error rates for cursor control tasks. This study explores the potential of a speech-controlled grid-based cursor control mechanism. An experiment evaluated two alternative grid-based solutions, both using 3-3 grids. One provided a single cursor in the middle of the grid. The second allows users to select a target using any of nine cursors. The results confirm that the nine-cursor solution allowed users to select targets of varying size, distance and direction significantly faster than the one-cursor solution. Overall results are encouraging when compared to earlier evaluations of other speech-based cursor control solutions.

Speech recognition systems have improved dramatically, but recent studies confirm that error correction activities still account for 66--75% of the users' time, and 50% of that time is spent just getting to the errors that need to be corrected. While researchers have suggested that confidence scores could prove useful during the error correction process, the focus is typically on error detection. More importantly, empirical studies have failed to confirm any measurable benefits when confidence scores are used in this way within dictation-oriented applications. In this article, we provide data that explains why confidence scores are unlikely to be useful for error detection. We propose a new navigation technique for use when speech-only interactions are strongly preferred and common, desktop-sized displays are available. The results of an empirical study that highlights the potential of this new technique are reported. An informal comparison between the current study and previous research suggests the new technique reduces time spent on navigation by 18%. Future research should include additional studies that compare the proposed technique to previous non-speech and speech-based navigation solutions.

Speech recognition technology continues to improve, but users still experience significant difficulty using the software to create and edit documents. In fact, a recent study confirmed that users spent 66% of their time on correction activities and only 33% on dictation. Of particular interest is the fact that one third of the users' time was spent simply navigating from one location to another. In this article, we investigate the efficacy of hands-free, speech-based navigation in the context of dictation-oriented activities. We provide detailed data regarding failure rates, reasons for failures, and the consequences of these failures. Our results confirm that direction-oriented navigation (e.g., Move up two lines) is less effective than target-oriented navigation (e.g. Select target). We identify the three most common reasons behind the failure of speech-based navigation commands: recognition errors, issuing of invalid commands, and pausing in the middle of issuing a command. We also document the consequences of failed speech-based navigation commands. As a result of this analysis, we identify changes that will reduce failure rates and lessen the consequences of some remaining failures. We also propose a more substantial set of changes to simplify direction-based navigation and enhance the target-based navigation. The efficacy of this final set of recommendations must be evaluated through future empirical studies.

Organizations are rushing to establish a presence on the World Wide Web (WWW). Researchers, designers, and users all recognize the importance of network delays, with longer delays frequently being associated with more negative user experiences. Although some delay is unavoidable, design decisions do contribute to the total delay users experience. In this article, a collection of tools that allow individuals to experience realistic network delays during informal evaluations, usability studies, and controlled experiments are described. These tools allow practitioners to more effectively assess usability in the context of realistic network delays, researchers to more effectively investigate the factors that affect the usability of information and applications delivered via the WWW, and educators to more effectively convey the importance of design decisions in the context of the WWW. This article describes how these tools may be used as well as the tools themselves, including the algorithms that make them effective. 2 approaches for validating simulations with results are presented. The first validation suggests that the simulation process utilized in the wide-area network delay simulator tools (Borella & Sears, 1997) effectively reproduces the network delays observed when retrieving material via the WWW. The second validation provides even stronger support, indicating that the simulation process can be used to reproduce a specific set of network conditions more accurately than the network itself. Directions for additional research are also discussed.

As mobile, handheld computing devices become more common and are used for an ever-increasing variety of tasks, new mechanisms for data entry must be investigated. Personal digital assistants often provide a small stylus-activated soft keyboard, as do some mobile phones that include touch screens. However, there is little data regarding the importance of keyboard size or the users' tasks, the effectiveness of these keyboards, or user reactions to these keyboards. In this article, an experiment designed to investigate these issues in the context of a palm-style QWERTY keyboard is described. In this study, 30 novices completed 6 realistic tasks using either a small, medium, or large soft keyboard. The results not only confirm that keyboard size does not affect data entry rates but that making the keyboard smaller does not increase error rates or negatively impact preference ratings. However, tasks that required users to switch between the alphabetic keyboard and the numeric keyboard do result in significantly slower data entry rates. A model that accurately predicts the time required to enter predefined text is presented, and directions for future research are discussed.

Speech recognition can be a powerful tool for individuals with physical disabilities that hinder their ability to use traditional input devices. State-of-the-art speech recognition systems typically provide mechanisms for both data entry and cursor control, but the researchers continue to investigate methods of improving these interactions. Numerous researchers are investigating methods to improve the underlying technologies that make speech recognition possible and others focus on understanding the difficulties users experience using dictation-oriented applications, but few researchers have investigated the issues involved in speech-based cursor control. In this article, we describe a study that investigates the efficacy of two variations of a standard speech-based cursor control mechanism. One employs the standard mouse cursor while the second provides a predictive cursor designed to help users compensate for the delays often associated with speech recognition. As expected, larger targets and shorter distances resulted in shorter target selection times while larger targets also resulted in fewer errors. Although there were no differences between the standard and predictive cursors, a relationship between the delays associated with spoken input, the speed at which the cursor moves, and the minimum size for targets that can be reliably selected emerged that can guide the application of similar speech-based cursor control mechanisms as well as future research.

In this article, we report on an empirical comparison of two common gesture recognition techniques. Thirty-one novices completed six realistic tasks using either Jot or Graffiti. An analysis of error-corrected data entry rates indicates that participants using Jot completed the tasks significantly faster than those using Graffiti. An analysis of uncorrected errors yielded no significant differences while several questions assessing subjective satisfaction yielded significantly more positive results for Jot. A new event called Period of Difficulty (PoD) is proposed to help identify situations were novices experience significant difficulty. Users experience more PoD when entering basic alphanumeric characters using Graffiti than they do using Jot. In contrast, Jot users experience more PoD when entering symbols than Graffiti users. Further, a detailed analysis of the PoD provides insights regarding the definition and use of the inherent accuracy metric while highlighting opportunities to improve the underlying technologies. We conclude by providing specific recommendations for improving the usability of Jot and Graffiti for novice users and outlining several additional directions for future research.

As portable, handheld computing devices become more common, alternatives to traditional keyboards must be explored. These alternatives must be compact, lightweight and sufficiently efficient to support the users' tasks. One alternative is the use of small physical keyboards or soft keyboards presented on touch-sensitive surfaces. Many alternative layouts have been explored, including the QWERTY, Dvorak, telephone and various alphabetic organizations. Soukoreff and MacKenzie proposed a model to predict typing times for alternative layouts, but have experienced limited success matching their predictions to observed performance. This paper proposes a revision of the visual search component of their model that considers the familiarity of the organization and the number of letters represented by each key. Results are reported of an experiment that supports the claim that both familiarity and the number of letters per key must be considered when predicting visual search times for alternative keyboard layouts.

This research experimentally examines the effects of network delays, document type, and various user characteristics on the perceived usability of distributed documents on the internet. Six experimental conditions were analysed: text only documents and documents including text and graphics at three levels of delay. Users were undergraduate and graduate students who reported spending zero to 50 hours per week on the internet. Usability was assessed by analysing responses to questions about ease of locating information, information organization, information quality, and navigation problems. The results showed significant interactions of network delay and document type on subjects' perceptions of quality, organization, navigation, and several additional factors that are important to organizations providing information on the internet. Both the number of hours subjects reported spending using the internet and subjects' self-reported command of the English language were significantly correlated with perceptions of various aspects of the internet sites examined. While the results indicate that internet users may prefer highly graphical web sites, it appears that they are unwilling to tolerate substantial delays. As a result, users in the study preferred plain text documents as delays increased.

Network quality of service, as manifest in the delays users experience, effects both user perceptions and performance. Unfortunately, existing research on the usability of network-based documents and applications does not always adequately address the issue of network delays. In this article, we assert that researchers must document, and should consider manipulating, the delays users experience during studies exploring the usability of network-based computing systems. This article provides an overview of the factors that contribute to the delays users experience and the issues involved in modeling these delays. It also provides advice on how delays should be documented and discusses the advantages and disadvantages of the various techniques available for integrating delays into usability studies and controlled experiments. The existing literature reports numerous inconsistent results, which may be due to different experimental designs, participants, tasks, independent variables, and dependent variables. Therefore, this article concludes by outlining the experimental design considerations that must be considered as the relation between network quality of service and the usability of network-based computing systems is investigated. The result is a framework that will guide future research and allow more effective comparisons of the results of that research.

Through 2 experiments, we examined both international differences and the effects of high-end graphical enhancements on the perceived usability of World Wide Web (WWW) sites. To accomplish this goal, we recruited Internet users from Switzerland and the United States to explore 1 of 2 versions of a Web site with the goal of retrieving specific information from the site. The first Web site was a self-contained subset of a large corporate Web site, and the second was a systematically simplified version of the first. After retrieving the required information from the site, participants responded to questions regarding their perception of the Web site's usability and its information presentation. Their responses provided detailed insights into significant differences between WWW users from 2 different cultures with respect to how they perceive the same Web sites. The importance of basic user demographics is documented, and empirical evidence is provided that devalues some high-end graphical enhancements.

Inspection-based evaluation techniques are popular because they can be fast, require limited formal training, and can find numerous usability problems. Cognitive walkthroughs are one of the most studied techniques, and as a result, the technique has undergone a series of revisions. One such revision, made to speed the evaluation process and reduce the need for formal training in cognitive psychology, incorporated detailed step-by-step task descriptions to guide the evaluation process. This article reports on the first study that investigated the effects of this change when evaluators were learning to apply the technique. The results indicate that providing detailed task descriptions rather than shorter descriptions, as are often used in usability tests, significantly changes the types of problems found. Evaluators given detailed task descriptions found significantly more problems related to the feedback provided by the system but significantly fewer problems related to difficulties locating the necessary controls to complete a task. In addition, evaluators given detailed task descriptions found significantly more low-severity problems. Implications for both researchers and practitioners are discussed.

Inspection-based evaluation techniques are popular because they require less formal training, are quick, can be used throughout the development process, do not require test users, and can result in finding numerous usability problems. A new technique is described that combines the benefits of heuristic evaluations, cognitive walkthroughs, and usability walkthroughs. This technique, a heuristic walkthrough, provide more structure than heuristic evaluations but less than cognitive walkthroughs. The result is an effective task-oriented evaluation technique that is easy to learn and apply. Methods are proposed for comparing the validity, thoroughness, and reliability of evaluation techniques. Finally, heuristic walkthroughs are compared to heuristic evaluations and cognitive walkthroughs in a controlled study. The results indicate that heuristic walkthroughs are more thorough than cognitive walkthroughs and more valid than heuristic evaluations. In other words, heuristic walkthroughs resulted in finding more problems than cognitive walkthroughs and fewer false positives than heuristic evaluations.

Visual Analysis adds breadth to a computer graphics course by teaching students to compare and contrast the visual effects of rendering algorithms. Using slides to teach visual analysis minimizes the amount of required lecture time, and the interactive tool TERA facilitates further study outside of class. Visual analysis enhances depth as well as breadth of knowledge, because students become familiar with an algorithm's visual effect before they implement it.

Automating any part of the user interface design and evaluation process can help reduce development costs.This paper presents a metric-based tool called AIDE (semi-Automated Interface Designer and Evaluator) which assists designers in creating and evaluating layouts for a given set of interface controls.AIDE is an initial attempt to demonstrate the potential of incorporating metrics into user interface development tools, Analyzing the interfaces produced using AIDE provides encouraging feedback about the potential of this technique.

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When some items in a menu are selected more frequently than others, as is often the case, designers or individual users may be able to speed performance and improve preference ratings by placing several high-frequency items at the top of the menu. Design guidelines for split menus were developed and applied. Split menus were implemented and tested in two in situ usability studies and a controlled experiment. In the usability studies performance times were reduced by 17 to 58% depending on the site and menus. In the controlled experiment split menus were significantly faster than alphabetic menus and yielded significantly higher subjective preferences. A possible resolution to the continuing debate among cognitive theorists about predicting menu selection times is offered. We conjecture and offer evidence that, at least when selecting items from pull-down menus, a logarithmic model applies to familiar (high-frequency) items, and a linear model to unfamiliar (low-frequency) items.

Two studies investigated the effect keyboard size has on typing speed and error rates for touchscreen keyboards using the lift-off strategy. A cursor appeared when users touched the screen and a key was selected when they lifted their finger from the screen. Four keyboard sizes were investigated ranging from 24.6 cm to 6.8 cm wide. Results indicate that novices can type approximately 10 words per minute (WPM) on the smallest keyboard and 20 WPM on the largest. Experienced users improved to 21 WPM on the smallest keyboard and 32 WPM on the largest. These results indicate that, although slower, small touchscreen keyboards can be used for limited data entry when the presence of a regular keyboard is not practical. Applications include portable pocket-sized or palmtop computers, messaging systems, and personal information resources. Results also suggest the increased importance of experience on these smaller keyboards. Research directions are suggested.

Numerous methods for evaluating user interfaces have been investigated to develop a metric that incorporates simple task descriptions which can assist designers in organizing their user interface. The metric, Layout Appropriateness (LA), requires a description of the sequences of actions users perform and how frequently each sequence is used. This task description can either be from observations of an existing system or from a simplified task analysis. The appropriateness of a given layout is computed by weighting the cost of each sequence of actions by how frequently the sequence is performed, which emphasizes frequent methods of accomplishing tasks while incorporating less frequent methods in the design. In addition to providing a comparison of proposed or existing layouts, an LA-optimal layout can be presented to the designer. The designer can compare the LA-optimal and existing layouts or start with the LA-optimal layout and modify it to take additional factors into consideration.>

The study explored touchscreen keyboards using high precision touch-screen strategies. Phase one evaluated three possible monitor positions: 30°, 45°, and 75° from horizontal. Results indicate that the 75° angle, approximately the standard monitor position, resulted in more fatigue and lower preference ratings. Phase two collected touch bias and key size data for the 30° angle. Subjects consistently touched below targets, and touched to the left of targets on either side of the screen. Using these data, a touchscreen keyboard was designed. Phase three compared this keyboard with a mouse-activated keyboard, and the standard QWERTY keyboard for typing relatively short strings of 6,19, and 44 characters. Results indicate that users can type approximately 25 words/minute (wpm) with the touchscreen keyboard, compared to 17 wpm using the mouse, and 58 wpm when using the keyboard. Possible improvements to touchscreen keyboards are suggested.