Andrew Sears
Has also published under the name of:
"A. Sears"
Personal Homepage:
research.umbc.edu/~asears/Current place of employment:
UMBCAndrew Sears is a Professor and Chair of the Information Systems Department at UMBC. Dr. Sears' research explores issues related to human-computer interaction with recent projects investigating issues associated with mobile computing, speech recognition, information technology (IT) accessibility, and the difficulties IT users experience as a result of their work environment or tasks. His research projects have been supported by a variety of companies (e.g., IBM, Intel Corporation, Microsoft Corporation, Motorola) and government agencies (e.g., the National Science Foundation, the US Department of Education, various state agencies in Maryland). He is Editor-in-Chief (with Vicki Hanson) of the ACM Transactions on Accessible Computing and serves on the editorial boards of the International Journal of Human-Computer Studies, the International Journal of Human-Interaction, Universal Access in the Information Society, and the International Journal of Mobile Human Computer Interaction. He served as Conference and Technical Program Co-Chair of the Association for Computing Machinery's Conference on Human Factors in Computing Systems (CHI 2001), General Chair and Program Chair for the ACM SIGACCESS Conference on Assistive Technology (Assets 2004 and ASSETS 2005 respectively), and has been on the program board for a variety of events including the Mobiquitous, MobileHCI, ERCIM User Interfaces for All, HCII, and UAIS conferences and workshops. He earned his BS in Computer Science from Rensselaer Polytechnic Institute and his Ph.D. in Computer Science with an emphasis on Human-Computer Interaction from the University of Maryland - College Park.
Publications by Andrew Sears (bibliography)
» 2008 «
Price, Kathleen J. and Sears, Andrew (2008): Performance-based functional assessment: an algorithm for measuring physical capabilities. In: Tenth Annual ACM SIGACCESS Conference on Assistive Technologies 2008. pp. 217-224. Available online
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.
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Feng, Jinjuan, Zhu, Shaojian, Hu, Ruimin and Sears, Andrew (2008): Speech technology in real world environment: early results from a long term study. In: Tenth Annual ACM SIGACCESS Conference on Assistive Technologies 2008. pp. 233-234. Available online
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.
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Sears, Andrew and Hanson, Vicki (2008): Introduction. In ACM Transactions on Accessible Computing, 1 (1) p. 1
Sears, Andrew, Lazar, Jonathan, Ozok, Ant and Meiselwitz, Gabriele (2008): Human-Centered Computing: Defining a Research Agenda. In International Journal of Human-Computer Interaction, 24 (1) pp. 2-16
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.
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» 2007 «
Sears, Andrew and Jacko, Julie A. (2007): The Human Computer Interaction Handbook: Fundamentals, Evolving Technologies and Emerging Applications. CRC Press
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Sears, Andrew and Jacko, Julie A. (2007): The Human-Computer Interaction Handbook: Fundamentals, Evolving Technologies and Emerging Applications (2nd Edition). Lawrence Erlbaum Associates
Lin, Min and Sears, Andrew (2007): Constructing Chinese characters: keypad design for mobile phones. In Behaviour and Information Technology, 26 (2) pp. 165-178
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.
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Lin, Min, Goldman, Rich, Price, Kathleen J., Sears, Andrew and Jacko, Julie A. (2007): How do people tap when walking? An empirical investigation of nomadic data entry. In International Journal of Human-Computer Studies, 65 (9) pp. 759-769
When mobile devices are used on the move, a user's limited visual resources are split between interacting with the mobile devices and maintaining awareness of the surrounding environment. In this study, we examined stylus-based tapping operations on a PDA under three mobility situations: seated, walking on a treadmill, and walking through an obstacle course. The results revealed that Fitts' Law continues to be effective even under the most challenging obstacle course condition. While target selection times did not differ between the various mobility conditions, overall task completion times, error rates, and several measures of workload differed significantly. Diminished performance under the obstacle course condition was attributed to increased demands on attention associated with navigating through the obstacle course. Results showed that the participants in the obstacle course condition were able to tap on a 6.4 mm-diameter target with 90% accuracy, but they reduced their walking speed by 36% and perceived an increased workload. Extending earlier research, we found that treadmill-based conditions were able to generate representative data for task selection times, but accuracy differed significantly from the more realistic obstacle course condition.
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Sears, Andrew, Hanson, Vicki L. and Myers, Brad A. (2007): Introduction to special issue on computers and accessibility. In ACM Transactions on Computer-Human Interaction, 14 (3) p. 11
Barnard, Leon, Yi, Ji Soo, Jacko, Julie A. and Sears, Andrew (2007): Capturing the effects of context on human performance in mobile computing systems. In Personal and Ubiquitous Computing, 11 (2) pp. 81-96
» 2006 «
Feng, Jinjuan, Sears, Andrew and Karat, Clare-Marie (2006): A longitudinal evaluation of hands-free speech-based navigation during dictation. In International Journal of Human-Computer Studies, 64 (6) pp. 553-569
Despite a reported recognition accuracy rate of 98%, speech recognition technologies have yet to be widely adopted by computer users. When considering hands-free use of speech-based solutions, as is the case for individuals with physical impairments that interfere with the use of traditional solutions such as a mouse, the considerable time required to complete basic navigation tasks presents a significant barrier to adoption. Several solutions were proposed to improve navigation efficiency based on the results of a previous study. In the current study, a longitudinal experiment was conducted to investigate the process by which users learn to use hands-free speech-based navigation in the context of large vocabulary, continuous dictation tasks as well the efficacy of the proposed solutions. Due to the influence initial interactions have on the adoption of speech-based solutions, the current study focused on these critical, initial, interactions of individuals with no prior experience using speech-based dictation solutions. Our results confirm the efficacy of the solutions proposed earlier while providing valuable insights into the strategies users employ when using speech-based navigation commands as well as design decisions that can influence these patterns.
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Price, Kathleen J., Lin, Min, Feng, Jinjuan, Goldman, Rich, Sears, Andrew and Jacko, Julie A. (2006): Motion does matter: an examination of speech-based text entry on the move. In Universal Access in the Information Society, 4 (3) pp. 246-257
Desktop interaction solutions are often inappropriate for mobile devices due to small screen size and portability needs. Speech recognition can improve interactions by providing a relatively hands-free solution that can be used in various situations. While mobile systems are designed to be transportable, few have examined the effects of motion on mobile interactions. This paper investigates the effect of motion on automatic speech recognition (ASR) input for mobile devices. Speech recognition error rates (RER) have been examined with subjects walking or seated, while performing text input tasks and the effect of ASR enrollment conditions on RER. The obtained results suggest changes in user training of ASR systems for mobile and seated usage.
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» 2005 «
Lin, Min and Sears, Andrew (2005): Chinese character entry for mobile phones: a longitudinal investigation. In Interacting with Computers, 17 (2) pp. 121-146
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.
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Feng, Jinjuan, Karat, Clare-Marie and Sears, Andrew (2005): How productivity improves in hands-free continuous dictation tasks: lessons learned from a longitudinal study. In Interacting with Computers, 17 (3) pp. 265-289
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.
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Barnard, Leon, Yi, Ji Soo, Jacko, Julie A. and Sears, Andrew (2005): An empirical comparison of use-in-motion evaluation scenarios for mobile computing devices. In International Journal of Human-Computer Studies, 62 (4) pp. 487-520
There is a clear need for evaluation methods that are specifically suited to mobile device evaluation, largely due to the vast differences between traditional desktop computing and mobile computing. One difference of particular interest that needs to be accounted for is that mobile computing devices are frequently used while the user is in motion, in contrast to desktop computing. This study aims to validate the appropriateness of two evaluation methods that vary in representativeness of mobility, one that uses a treadmill to simulate motion and another that uses a controlled walking scenario. The results lead to preliminary guidelines based on study objectives for researchers wishing to use more appropriate evaluation methodologies for empirical, data-driven mobile computing studies. The guidelines indicate that using a treadmill for mobile evaluation can yield representative performance measures, whereas a controlled walking scenario is more likely to adequately simulate the actual user experience.
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Lin, Min and Sears, Andrew (2005): Graphics matter: a case study of mobile phone keypad design for Chinese input. In: Proceedings of ACM CHI 2005 Conference on Human Factors in Computing Systems 2005. pp. 1593-1596. Available online
Developing more effective and efficient Chinese character input methods has the potential to help Chinese mobile phone users (currently 320 millions) input text messages. iTAP(R) supports input based on the writing structure of Chinese characters. Current keypad graphics include three items: digits (0-9), letters (A-Z), and symbols that represent the minimum writing units of Chinese characters (strokes). Our study revealed the difficulties of mapping these strokes to individual keys using the current symbols. We present a case study illustrating the user-centered redesign of these symbols. The new symbols allow for faster entry speeds and lower error rates as compared to the current commercial solution. Results with our solution were also favorable when compared to Pinyin, a popular cross-cultural solution relying on the Roman alphabet. The new design is in the process of being integrated into commercial mobile phones for users who would prefer native input methods for Chinese.
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Yi, Ji Soo, Choi, Young Sang, Jacko, Julie A. and Sears, Andrew (2005): Context awareness via a single device-attached accelerometer during mobile computing. In: Proceedings of 7th conference on Human-computer interaction with mobile devices and services 2005. pp. 303-306. Available online
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.
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Fischer, Arnout R. H., Price, Kathleen J. and Sears, Andrew (2005): Speech-Based Text Entry for Mobile Handheld Devices: An Analysis of Efficacy and Error Correction Techniques for Server-Based Solutions. In International Journal of Human-Computer Interaction, 19 (3) pp. 279-304
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.
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Yi, Ji Soo, Choi, Young Sang, Jacko, Julie A. and Sears, Andrew (2005): Context awareness via a single device-attached accelerometer during mobile computing. In: Tscheligi, Manfred, Bernhaupt, Regina and Mihalic, Kristijan (eds.) Proceedings of the 7th Conference on Human-Computer Interaction with Mobile Devices and Services - Mobile HCI 2005 September 19-22, 2005, Salzburg, Austria. pp. 303-306. Available online
Zhou, Lina, Feng, Jinjuan, Sears, Andrew and Shi, Yongmei (2005): Applying the Naïve Bayes Classifier to Assist Users in Detecting Speech Recognition Errors. In: HICSS 2005 - 38th Hawaii International Conference on System Sciences 3-6 January, 2005, Big Island, HI, USA. . Available online
» 2004 «
Price, Kathleen J., Lin, Min, Feng, Jinjuan, Goldman, Rich, Sears, Andrew and Jacko, Julie A. (2004): Data Entry on the Move: An Examination of Nomadic Speech-Based Text Entry. In: Proceedings of the 8th ERCIM Workshop on User Interfaces for All 2004. p. 460. Available online
Desktop interaction solutions are often inappropriate for mobile devices due to small screen size and portability needs. Speech recognition can improve interactions by providing a relatively hands-free solution that can be used in various situations. While mobile systems are designed to be transportable, few have examined the effects of motion on mobile interactions. We investigated the effect of motion on automatic speech recognition (ASR) input for mobile devices. We examined speech recognition error rates (RER) with subjects walking or seated, while performing text input tasks and the effect of ASR enrollment conditions on RER. RER were significantly lower for seated conditions. There was a significant interaction between enrollment and task conditions. When users enrolled while seated, but completed walking tasks, RER increased. In contrast, when users enrolled while walking, but completed seated tasks, RER decreased. These results suggest changes in user training of ASR systems for mobile and seated usage.
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Dai, Liwei, Goldman, Rich, Sears, Andrew and Lozier, Jeremy (2004): Speech-based cursor control: a study of grid-based solutions. In: Sixth Annual ACM Conference on Assistive Technologies 2004. pp. 94-101. Available online
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.
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Feng, Jinjuan and Sears, Andrew (2004): Using confidence scores to improve hands-free speech based navigation in continuous dictation systems. In ACM Transactions on Computer-Human Interaction, 11 (4) pp. 329-356
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.
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» 2003 «
Sears, Andrew, Feng, Jinhuan, Oseitutu, Kwesi and Karat, Clare-Marie (2003): Hands-Free, Speech-Based Navigation During Dictation: Difficulties, Consequences, and Solutions. In Human-Computer Interaction, 18 (3) pp. 229-257
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.
Copyrights may apply
A.Jacko, Julie and Sears, Andrew (2003): The human-computer interaction handbook: fundamentals, evolving technologies and emerging applications. Lawrence Erlbaum Associates
Jacko, Julie A. and Sears, Andrew (eds.) (2003): The human-computer interaction handbook: fundamentals, evolving technologies, and emerging applications. Lawrence Erlbaum Associates
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Feng, J. and Sears, Andrew (2003): Using Confidence Scores to Improve Hands-Free Speech-Based Navigation. In: Proceedings of the Tenth International Conference on Human-Computer Interaction 2003. pp. 641-645.
Karimullah, A., Sears, Andrew, Lin, M. and Goldman, R. (2003): Speech-based cursor control: Understanding the effects of variable cursor speed on target selection. In: Proceedings of the Tenth International Conference on Human-Computer Interaction 2003. pp. 681-685.
Price, K. and Sears, Andrew (2003): Speech-based Text Entry for Mobile Devices. In: Proceedings of the Tenth International Conference on Human-Computer Interaction 2003. pp. 766-770.
Campbell, J., Stanziola, E. and Sears, Andrew (2003): Data Analysis and Visualization for Usability Evaluation for Collaborative Systems. In: Proceedings of the Tenth International Conference on Human-Computer Interaction 2003. pp. 869-873.
Sears, Andrew, Lin, M., Jacko, Julie A. and Xiao, Y. (2003): When Computers Fade... Pervasive Computing and Situationally-Induced Impairments and Disabilities. In: Proceedings of the Tenth International Conference on Human-Computer Interaction 2003. pp. 1298-1302.
Lu, Y.-C., Xiao, Y., Sears, Andrew and Jacko, Julie A. (2003): An Observational and Interview Study on Personal Digital Assistant (PDA) Uses by Clinicians in Different Contexts. In: Proceedings of the Tenth International Conference on Human-Computer Interaction 2003. pp. 93-97.
Sears, Andrew and Zha, Ying (2003): Data Entry for Mobile Devices Using Soft Keyboards: Understanding the Effects of Keyboard Size and User Tasks. In International Journal of Human-Computer Interaction, 16 (2) pp. 163-184
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.
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Sears, Andrew (2003): Simulating Network Delays: Applications, Algorithms, and Tools. In International Journal of Human-Computer Interaction, 16 (2) pp. 301-323
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.
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» 2002 «
Sears, Andrew and Arora, Renee (2002): Data entry for mobile devices: an empirical comparison of novice performance with Jot and Graffiti. In Interacting with Computers, 14 (5) pp. 413-433
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.
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Karimullah, Azfar S. and Sears, Andrew (2002): Speech-based cursor control. In: Fifth Annual ACM Conference on Assistive Technologies 2002. pp. 178-185. Available online
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.
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Sears, Andrew, Lin, M. and Karimullah, A. S. (2002): Speech-based cursor control: understanding the effects of target size, cursor speed, and command selection. In Universal Access in the Information Society, 2 (1) pp. 30-43
Speech recognition can be a powerful tool when physical disabilities, environmental factors, or the tasks in which an individual is engaged hinders the individual's ability to use traditional input devices. While state-of-the-art speech-recognition systems typically provide mechanisms for both data entry and cursor control, speech-based interactions continue to be slow when compared to similar keyboard- or mouse-based interactions. Although numerous researchers continue to investigate methods of improving speech-based interactions, most of these efforts focus on the underlying technologies or dictation-oriented applications. As a result, the efficacy of speech-based cursor control has received little attention. In this article, we describe two experiments that provide insight into the issues involved when using speech-based cursor control. The first compares two variations of a common 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. Interestingly, there were no differences between the standard and predictive cursors. The second experiment investigates the delays associated with spoken input, explains why the original predictive-cursor implementation failed to provide the expected benefits, and provides insight that guided the design of a new predictive cursor.
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» 2001 «
Sears, Andrew, Jacko, Julie A., Chung, James C. and Moro, Francisco (2001): The role of visual search in the design of effective soft keyboards. In Behaviour and Information Technology, 20 (3) pp. 159-166
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.
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Sears, Andrew and Arora, R. (2001): An Evaluation of Gesture Recognition for PDAs. In: Proceedings of the Ninth International Conference on Human-Computer Interaction 2001. pp. 1-5.
Zha, Y. and Sears, Andrew (2001): Data Entry for Mobile Devices Using Soft Keyboards: Understanding the Effect of Keyboard Size. In: Proceedings of the Ninth International Conference on Human-Computer Interaction 2001. pp. 16-20.
Sears, Andrew, Karat, Clare-Marie, Oseitutu, Kwesi, Karimullah, Azfar and Feng, Jinjuan (2001): Productivity, satisfaction, and interaction strategies of individuals with spinal cord injuries and traditional users interacting with speech recognition software. In Universal Access in the Information Society, 1 (1) pp. 4-15
Speech recognition is an important technology that is becoming increasingly effective for dictation-oriented activities. While recognition accuracy has increased dramatically in recent years, recent studies confirm that traditional computer users are still faster using a keyboard and mouse and spend more time correcting errors than dictating. Further, as these users become more experienced they frequently adopt multimodal strategies that require the keyboard and mouse when correcting errors. While speech recognition can be a convenient alternative for traditional computer users, it can be a powerful tool for individuals with physical disabilities that limit their ability to use a keyboard and mouse. However, research into the performance, satisfaction, and usage patterns of individuals with physical disabilities has not been reported. In this article, we report on a study that provides initial insights into the efficacy of existing speech recognition systems with respect to individuals with physical disabilities. Our results confirm that productivity does not differ between traditional users and those with physical disabilities. In contrast, numerous differences were observed when users rated their satisfaction with the system and when usage patterns were analyzed.
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Emery, V. Katie, Jacko, Julie A., Kongnakorn, Thitima, Kuruchittham, Vipat, Landry, Steven, Nickles, George McLeland, Sears, Andrew and Whittle, Justin (2001): Identifying Critical Interaction Scenarios for Innovative User Modeling. In: Stephanidis, Constantine (ed.) HCI International 2001 - Proceedings of the 9th International Conference on Human-Computer Interaction August 5-10, 2001, New Orleans, USA. pp. 481-485.
Oseitutu, Kwesi, Feng, Jinjuan, Sears, Andrew and Karat, Clare-Marie (2001): Speech recognition for data entry by individuals with spinal cord injuries. In: Stephanidis, Constantine (ed.) HCI International 2001 - Proceedings of the 9th International Conference on Human-Computer Interaction August 5-10, 2001, New Orleans, USA. pp. 402-406.
» 2000 «
Jacko, Julie A., Sears, Andrew and Borella, Michael S. (2000): The Effect of Network Delay and Media on User Perceptions of Web Resources. In Behaviour and Information Technology, 19 (6) pp. 427-439
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.
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Sears, Andrew and Jacko, Julie A. (2000): Understanding the Relation Between Network Quality of Service and the Usability of Distributed Multimedia Documents. In Human-Computer Interaction, 15 (1) pp. 43-68
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.
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Sears, Andrew (2000): Introduction: Empirical Studies of WWW Usability. In International Journal of Human-Computer Interaction, 12 (2) pp. 167-171
Sears, Andrew, Jacko, Julie A. and Dubach, Erica M. (2000): International Aspects of World Wide Web Usability and the Role of High-End Graphical Enhancements. In International Journal of Human-Computer Interaction, 12 (2) pp. 241-261
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.
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» 1999 «
Sears, Andrew and Hess, David J. (1999): Cognitive Walkthroughs: Understanding the Effect of Task-Description Detail on Evaluator Performance. In International Journal of Human-Computer Interaction, 11 (3) pp. 185-200
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.
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Sears, Andrew (1999): Degrees in Human-Computer Interaction: A Common Name is Emerging and Opportunities are Expanding. In ACM SIGCHI Bulletin, 31 (1) pp. 7-8
Sears, Andrew and Bishof-Risario, J. (1999): Redesigning speech recognition for use by individuals with spinal cord injuries. In: 1999. pp. 966-969.
» 1998 «
Jacko, Julie A. and Sears, Andrew (1998): Designing Interfaces for an Overlooked User Group: Considering the Visual Profiles of Partially Sighted Users. In: Third Annual ACM Conference on Assistive Technologies 1998. pp. 75-77. Available online
In this position paper we argue the importance of research focusing on the issues involved in designing computer systems for partially sighted computer users. Currently, there is a lack of data that explores how combinations of impaired visual processes affect preferences for, and performance with, graphical user interfaces. This lack of fundamental information about how an individual's visual profile determines the strategies and behaviors exhibited while using computers limits our ability to design effective user interfaces for partially sighted computer users. The objective of this position paper is to motivate research that addresses this deficiency in our knowledge base so that researchers can design enabling technologies in a systematic fashion for this unique user group as has been done for fully sighted users and blind users.
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Sears, Andrew (1998): New Perspectives on HCI Education. In ACM SIGCHI Bulletin, 30 (1) p. 4
Sears, Andrew (1998): An HCI Reading List. In ACM SIGCHI Bulletin, 30 (1) pp. 49-64
Williams, Marian G. and Sears, Andrew (1998): HCI Education and CHI 98. In ACM SIGCHI Bulletin, 30 (4) pp. 9-15
» 1997 «
Sears, Andrew (1997): Heuristic Walkthroughs: Finding the Problems Without the Noise. In International Journal of Human-Computer Interaction, 9 (3) pp. 213-234
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, provides 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.
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Sears, Andrew (1997): HCI Education: Where is it Headed?. In ACM SIGCHI Bulletin, 29 (1) pp. 7-9
Sears, Andrew (1997): Forums for Improving HCI Education. In ACM SIGCHI Bulletin, 29 (2) pp. 6-7
Sears, Andrew, Jacko, Julie A. and Mantei, Marilyn (1997): The SIGCHI Educational Resource Development Group. In ACM SIGCHI Bulletin, 29 (3) pp. 4-6
Sears, Andrew and Williams, Marian G. (1997): HCI Education and CHI 97. In ACM SIGCHI Bulletin, 29 (4) pp. 9-12
Sears, Andrew and Borella, Michael S. (1997): The Effect of Internet Delay on the Design of Distributed Multimedia Documents. In: Smith, Michael J., Salvendy, Gavriel and Koubek, Richard J. (eds.) HCI International 1997 - Proceedings of the Seventh International Conference on Human-Computer Interaction - Volume 2 August 24-29, 1997, San Francisco, California, USA. pp. 331-334.
Sears, Andrew, Jacko, Julie A. and Borella, Michael S. (1997): The Effect of Internet Delay on the Perceived Quality of Information. In: Smith, Michael J., Salvendy, Gavriel and Koubek, Richard J. (eds.) HCI International 1997 - Proceedings of the Seventh International Conference on Human-Computer Interaction - Volume 2 August 24-29, 1997, San Francisco, California, USA. pp. 335-338.
» 1996 «
Sears, Andrew (1996): Some Progress and Some New Questions. In ACM SIGCHI Bulletin, 28 (4) pp. 11-14
Sears, Andrew, Czerwinski, Mary, Dringus, Laurie P. and Thomas, Barbara Bernal (1996): Educating HCI Practitioners: Evaluating What Industry Needs and Academia. In ACM SIGCHI Bulletin, 28 (4) pp. 26-28
» 1995 «
Sears, Andrew (1995): AIDE: A Step Toward Metric-Based Interface Development Tools. In: Robertson, George G. (ed.) Proceedings of the 8th annual ACM symposium on User interface and software technology November 15 - 17, 1995, Pittsburgh, Pennsylvania, United States. pp. 101-110. Available online
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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Sears, Andrew (1995): "The Trouble with Computers," by T. K. Landauer. In International Journal of Human-Computer Interaction, 7 (4) pp. 407-408
Cohen, Maxine S., Dringus, Laurie P., Sears, Andrew and Hornstein, Susan B. (1995): Increasing Collaboration between Industry and Academia in HCI Education. In ACM SIGCHI Bulletin, 27 (4) pp. 29-30
» 1994 «
Sears, Andrew and Shneiderman, Ben (1994): Split Menus: Effectively Using Selection Frequency to Organize Menus. In ACM Transactions on Computer-Human Interaction, 1 (1) pp. 27-51
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.
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» 1993 «
Sears, Andrew, Revis, Doreen, Swatski, Janet, Crittenden, Rob and Shneiderman, Ben (1993): Investigating Touchscreen Typing: The Effect of Keyboard Size on Typing Speed. In Behaviour and Information Technology, 12 (1) pp. 17-22
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 24.6cm to 6.8cm 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.
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» 1992 «
Plaisant, Catherine and Sears, Andrew (1992): Touchscreen Interfaces for Alphanumeric Data Entry. In: Proceedings of the Human Factors Society 36th Annual Meeting 1992. pp. 293-297.
Touchscreens have been demonstrated as useful for many applications. Although a traditional mechanical keyboard is the device of choice when entering alphanumeric data, it may not be optimal when only limited data must be entered, or when the keyboard layout, character set, or size may be changed. A series of experiments has demonstrated the usability of touchscreen keyboards. The first study indicated that users who type 58 wpm on a traditional keyboard can type 25 wpm using a touchscreen and that the traditional monitor position is suboptimal for touchscreen use. A second study reported on typing rates for keyboards of various sizes (from 6.8 to 24.6 cm wide). Novices typed approximately 10 wpm on the smallest and 20 wpm on the largest of the keyboards. Users experienced with touchscreen keyboards typed 21 wpm on the smallest and 32 wpm on the largest. We then report on a recent study done with more representative users and more difficult tasks. Thirteen cashiers were recruited for this study and were required to complete ten trials in which they typed names and addresses with punctuation. Results indicate that the users improved rapidly from 9.5 wpm on the first trial to 13.8 wpm on the last trial, reaching their fastest performance after only 25 minutes. Although custom interfaces will be preferred for special types of data (e.g. telephone numbers, times, dates, colors) there will always be situations when limited quantities of text must be entered. In these situations a touchscreen keyboard can be used.
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» 1991 «
Sears, Andrew and Shneiderman, Ben (1991): High Precision Touchscreens: Design Strategies and Comparisons with a Mouse. In International Journal of Man-Machine Studies, 34 (4) pp. 593-613
Three studies were conducted comparing speed of performance, error rates and user preference ratings for three selection devices. The devices tested were a touchscreen, a touchscreen with stabilization (stabilization software filters and smooths raw data from hardware), and a mouse. The task was the selection of rectangular targets 1, 4, 16 and 32 pixels per side (0.4 x 0.6, 1.7 x 2.2, 6.9 x 9.0, 13.8 x 17.9 mm respectively). Touchscreen users were able to point at single pixel targets, thereby countering widespread expectations of poor touchscreen resolution. The results show no difference in performance between the mouse and touchscreen for targets ranging from 32 to 4 pixels per side. In addition, stabilization significantly reduced the error rates for the touchscreen when selecting small targets. These results imply that touchscreens, when properly used, have attractive advantages in selecting targets as small as 4 pixels per size (approximately one-quarter of the size of a single character). A variant of Fitts' Law is proposed to predict touchscreen pointing times. Ideas for future research are also presented.
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Sears, Andrew (1991): Improving Touchscreen Keyboards: Design Issues and a Comparison with Other Devices. In Interacting with Computers, 3 (3) pp. 253-269
The study explored touchscreen keyboards using high precision touchscreen strategies. Phase one evaluated three possible monitor positions: 30{deg}, 45{deg}, and 75{deg} from horizontal. Results indicate that the 75{deg} 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{deg} 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.
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User-contributed publications
Here is a list of publications that have been submitted by the author himself/herself or a website visitor:
Sears, A. and Law, C. (2005). Physical Disabilities in Human Computer Interaction. In: W. Karwowski (Ed). International Encyclopedia of Ergonomics and Human Factors, 2nd Edition, pp. 1217-1223.
Price, K. and Sears, A. (2005). Speech-based Text Entry for Mobile Handheld Devices: An analysis of efficacy and error correction techniques for server-based solutions. International Journal of Human-Computer Interaction, 19(3), 279-304.
Barnard, L., Yi, J.S., Jacko, J. A., Sears, A. (2005). An Empirical Comparison of Use-in-Motion Evaluation Scenarios for Mobile Computing Devices. International Journal of Human Computer Studies, 62, 487-520.
Dai, L., Goldman, R., Sears, A. and Lozier, J. (2005). Speech-based cursor control using grids: Modeling performance and comparisons with other solutions. Behaviour and Information Technology, 24(3), 219-230.
Lu, Y.-C., Xiao, Y., Sears, A., and Jacko, J. A. (2005). A Review and A Framework of Handheld Computer Adoption in Healthcare. International Journal of Medical Informatics, 74(5), 409-422.
Feng, J., Karat, C-M., and Sears, A. (2005). How Productivity Improves in Hands-free Continuous Dictation Tasks: Lessons Learned from a Longitudinal Study. Interacting with Computers, 17(3), 265-289.
Lin, M., and Sears, A. (2005). Chinese character entry for mobile phones: A longitudinal investigation. Interacting with Computers, 17(2), 121-146.
Feng, J. and Sears. A. (2004). Using confidence scores to improve hands-free speech-based recognition error specification. ACM Transactions on Computer-Human Interaction, 11(4), 1-28.
Price, K., Lin, M., Feng, J., Goldman, R., Sears, A. and Jacko, J. (2004). Data Entry on the Move: An Examination of Nomadic Speech-based Text Entry. Lecture Notes in Computer Science, 3196, 460-471.
Sears, A. (2003). Universal Usability and the WWW. In: J. Ratner (ed) Human Factors and Web Development 2nd Edition (pp. 21-46). Mahwah, NJ: Lawrence Erlbaum Associates Inc. Publishers.
Sears. A. and Young, M. (2003). Physical Disabilities and Computing Technologies: An Analysis of Impairments. In: J. Jacko and A. Sears (Eds) The Human-Computer Interaction Handbook: Fundamentals, Evolving Technologies and Emerging Applications. Mahwah, NJ: Lawrence Erlbaum Associates Inc. Publishers.
Jacko, J. and Sears, A. (2003). The Human-Computer Interaction Handbook: Fundamentals, Evolving Technologies and Emerging Applications. Mahwah, NJ: Lawrence Erlbaum Associates Inc. Publishers.
Sears, A., Feng, J., Oseitutu, K. & Karat, C. (2003). Hands-free speech-based navigation during dictation: Difficulties, consequences, and solutions. Human Computer Interaction, 18(3), 229-258.
Sears, A. (2003). Simulating network delays: Applications, algorithms, and tools. International Journal of Human-Computer Interaction, 16(2), 301-323.
Sears, A. and Zha, Y. (2003). Data entry for mobile devices using soft keyboards: Understanding the effects of keyboard size and user tasks. International Journal of Human-Computer Interaction, 16(2), 163-184.
Sears, A. and Jacko, J. (2003). Exploring the effects of hardware performance, application design, and cognitive demands on user productivity and perceptions. Journal of End User Computing, 15(2), 55-75.
Sears, A. & Arora, R. (2002). Data entry for mobile devices: An empirical comparison of novice performance with Jot and Graffiti. Interacting with Computers, 14(5), 413-433.
Sears, A., Lin, M. and Karimullah, A. S. (2002). Speech-Based Cursor Control: Understanding the effects of target size, cursor speed, and command selection. Universal Access in the Information Society, 2(1), 30-43.
Jacko, J. A., Salvendy, G., Sainfort, F., Emery, V. K., Akoumianakis, D., Duffy, V. D., Ellison, J., Gant, D. B., Gill, Z., Ji, G. Y., Jones, P. M., Karsh, B-T., Karshmer, A. I., Lazar, J., Peacock, B., Resnick, M. L., Sears, A., Smith, M. J., Stephanidis, C., Ziegler, J. (2002). Intranets and Organizational Learning: A Research and Development Agenda, International Journal of Human-Computer Interaction, 14, 1, 93-130. Mahwah, NJ: Lawrence Erlbaum Associates Inc. Publishers.
Jacko, J. A., Sears, A., Sorensen, S. J. (2001). A Framework for Usability: Healthcare Professionals and the Internet. Ergonomics, 44(11), 989-1007. London: Taylor and Francis.
Sears, A., Karat, C-M., Oseitutu, K., Karimullah, A., & Feng, J. (2001). Productivity, satisfaction, and interaction strategies of individual with spinal cord injuries and traditional users interacting with speech recognition software. Universal Access in the Information Society, 1, 4-15. Berlin, Germany: Springer-Verlag.
Sears, A., Jacko, J. A., Chu, J. & Moro, F. (2001). The role of visual search in the design of effective soft keyboards. Behaviour and Information Technology, 20(3), 159-166. London: Taylor and Francis.
Jacko, J. A., Sears, A. & Borella, M. S. (2000). The Effect of network delay and media on user perceptions of web resources. Behaviour and Information Technology, 19(6), 427-439. London: Taylor and Francis.
Sears, A. & Jacko, J. A. (2000). Understanding the relationship between network quality of service and the usability of distributed multimedia documents. Human Computer Interaction, 15, 43-68. Mahwah, NJ: Lawrence Erlbaum Associates Inc. Publishers.
Sears, A., Jacko, J. A. & Dubach, E. M. (2000). International aspects of WWW usability and the role of high-end graphical enhancements. International Journal of Human-Computer Interaction, 12, 2, 243-263. Mahwah, NJ: Lawrence Erlbaum Associates Inc. Publishers.
Sears, A. & Hess, D. (1999). Cognitive Walkthroughs: Understanding the effect of task description detail on evaluator performance. International Journal of Human-Computer Interaction, 11, 3, pp. 185-200. Mahwah, NJ: Lawrence Erlbaum Associates Inc. Publishers.
Sorensen, S. J., Jacko, J. A., Sears, A. (1998). Hospital pharmacists' use, perceptions, and opinions of the Internet. Pharmacotherapy, 18, 2, 438 (abstract). Kansas City, Missouri: American College of Clinical Pharmacy.
Sears, A. (1997). Heuristic Walkthroughs: Finding the problems without the noise. International Journal of Human-Computer Interaction, 9, 3, pp. 213-234. Mahwah, NJ: Lawrence Erlbaum Associates Inc. Publishers.
Wolfe, R., Grissom, S., Naps, T. & Sears, A. (1996). A Tested Tool for Teaching Computer Graphics. The Journal of Computing in Small Colleges, 12, 2, 70-77. Indiana: Consortium for Computing Sciences in Small Colleges.
Wolfe, R. & Sears, A. (1996). An effective tool for learning the visual effects of rendering algorithms. Computer Graphics, 30, 3, 54-55. New York: ACM Press.
Sears, A. & Shneiderman, B. (1994). Split menus: Effectively using selection frequency to organize menus. ACM Transactions on Computer-Human Interaction, 1, 1, 27-51. New York: ACM Press
Sears, A. (1994). Automated metrics for user interface design and evaluation. International Journal of Bio-Medical Computing, 34, 1-4, 149-157. Amsterdam: Elsevier Science Publishers.
Wolfe, R. & Sears, A. (1994). TERA: An interactive tool for exploring rendering algorithms. The Journal of Computing in Small Colleges, 10, 4, 41-46. Indiana: Consortium for Computing Sciences in Small Colleges.
Sears, A. (1993). Layout Appropriateness: A metric for evaluating user interface widget layout. IEEE - Transactions on Software Engineering, 19, 7, 707-719. New York: IEEE.
Sears, A., Revis, D., Swatski, J., Crittenden, R., & Shneiderman, B. (1991). Investigating Touchscreen Typing: The effect of keyboard size on typing speed. Behaviour and Information Technology, 12, 1, 17-22. London: Taylor and Francis.
Sears, A. (1991). Improving Touchscreen Keyboards: Design issues and a comparison with other devices, Interacting with Computers, 3, 3, 253-269. Amsterdam: Elsevier Science Publishers.
Sears, A., & Shneiderman, B. (1991). High Precision Touchscreens: Design Strategies and Comparisons with a Mouse, International Journal of Man Machine Studies, 34, 4, 593-613. Cambridge, UK: Academic Press.
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