Publication statistics
Pub. period:1989-1996
Pub. count:11
Number of co-authors:18
Co-authors
Number of publications with 3 favourite co-authors:
Paul Resnick:3Deborah Mrazek:2Don Ottens:1 Productive colleagues
Robert A. Virzi's 3 most productive colleagues in number of publications:
Paul Resnick:30Thomas S. Tullis:16Joseph S. Dumas:14
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Robert A. Virzi
Has also published under the name of:
"Robert Virzi"
Publications by Robert A. Virzi (bibliography)
Virzi, Robert A., Sokolov, Jeffrey L. and Karis, Demetrios (1996): Usability Problem Identification Using Both Low- and High-Fidelity Prototype. In: Tauber, Michael J., Bellotti, Victoria, Jeffries, Robin, Mackinlay, Jock D. and Nielsen, Jakob (eds.) Proceedings of the ACM CHI 96 Human Factors in Computing Systems Conference April 14-18, 1996, Vancouver, Canada. pp. 236-243.
“In two experiments, each using a different product (either a CD-ROM based electronic book or an interactive voice response system), we compared the usability problems uncovered using low- and high-fidelity prototypes. One group of subjects performed a series of tasks using a paper-based low-fidelity prototype, while another performed the same tasks using either a high-fidelity prototype or the actual product. In both experiments, substantially the same sets of usability problems were found in the low- and high-fidelity conditions. Moreover, there was a significant correlation between the proportion of subjects detecting particular problems in the low- and high-fidelity groups. In other words, individual problems were detected by a similar proportion of subjects in both the low- and high-fidelity conditions. We conclude that the use of low-fidelity prototypes can be effective throughout the product development cycle, not just during the initial stages of design.”
© All rights reserved Virzi et al. and/or ACM Press
Resnick, Paul and Virzi, Robert A. (1995): Relief from the Audio Interface Blues: Expanding the Spectrum of Menu, List, and Form Styles. In ACM Transactions on Computer-Human Interaction, 2 (2) pp. 145-176.
“Menus, lists, and forms are the workhorse dialogue structures in telephone-based interactive voice response applications. Despite diversity in applications, there is a surprising homogeneity in the menu, list, and form styles commonly employed. There are, however, many alternatives, and no single style fits every prospective application and user population. A design space for each dialogue structure organizes the alternatives and provides a framework for analyzing their benefits and drawbacks. In addition to phone-based interactions, the design spaces apply to any limited-bandwidth, temporally constrained display devices, including small-screen devices such as personal digital assistants (PDAs) and screen phones.”
© All rights reserved Resnick and Virzi and/or ACM Press
Dumas, Joseph S., Sorce, James and Virzi, Robert A. (1995): Expert Reviews: How Many Experts is Enough?. In: Proceedings of the Human Factors and Ergonomics Society 39th Annual Meeting 1995. pp. 228-232.
“We asked five usability specialists to review the user interface to a phone-based, interactive voice response system. The experts were instructed to conduct their review independently in three one-hour sessions and to record each usability problem on a Problem Description Sheet along with the elapsed time from the beginning of the hour. Each expert then spent one hour reviewing their problem sheets and making a summary list of problems. Finally, the experts spent two hours together on a conference call discussing their impressions and coming to consensus on a prioritized list of problems and solutions. The results showed that when allocating expert time, it is more effective to have a greater number of experts spend fewer hours than to use fewer experts for more hours. The individual summaries included the majority of the severe problems, but left out many less severe problems and added new problems. The group report did not surface any new problems, but described the problems as being caused by more basic design flaws and proposed solutions that focused on the conceptual model on which the design was based.”
© All rights reserved Dumas et al. and/or Human Factors Society
Virzi, Robert A., Sorce, James F. and Herbert, Leslie Beth (1993): A Comparison of Three Usability Evaluation Methods: Heuristic, Think-Aloud, and Performance Testing. In: Proceedings of the Human Factors and Ergonomics Society 37th Annual Meeting 1993. pp. 309-313.
“A high-fidelity prototype of an extended voice mail application was created. We tested it using three distinct usability testing paradigms so that we could compare the quantity and quality of the information obtained using each. The three methods employed were (1) heuristic evaluation, in which usability experts critique the user interface, (2) think-aloud testing, in which naive subjects comment on the system as they use it, and (3) performance testing, in which task completion times and error rates are collected as naive subjects interact with the system. The three testing methodologies were roughly equivalent in their ability to detect a core set of usability problems on a per evaluator basis. However, the heuristic and think-aloud evaluations were generally more sensitive, uncovering a broader array of problems in the user interface. Implications of these findings are discussed in terms of the costs of doing the evaluations and in light of other work on this topic.”
© All rights reserved Virzi et al. and/or Human Factors Society
Resnick, Paul and Virzi, Robert A. (1992): Skip and Scan: Cleaning Up Telephone Interfaces. In: Bauersfeld, Penny, Bennett, John and Lynch, Gene (eds.) Proceedings of the ACM CHI 92 Human Factors in Computing Systems Conference June 3-7, 1992, Monterey, California. pp. 419-426.
“The current generation of telephone interfaces is frustrating to use, in part because callers have to wait through the recitation of long prompts in order to find the options that interest them. In a visual medium, users would shift their gaze in order to skip uninteresting prompts and scan through large pieces of text. We present skip and scan, a new telephone interface style in which callers issue explicit commands to accomplish these same skipping and scanning activities. In a laboratory experiment, subjects made selections using skip and scan menus more quickly than using traditional, numbered menus, and preferred the skip and scan menus in subjective ratings. In a field test of a skip and scan interface, the general public successfully added and retrieved information without using any written instructions.”
© All rights reserved Resnick and Virzi and/or ACM Press
Virzi, Robert A., Resnick, Paul and Ottens, Don (1992): Skip and Scan Telephone Menus: User Performance as a Function of Experience. In: Proceedings of the Human Factors Society 36th Annual Meeting 1992. pp. 211-215.
“We present the results of a laboratory study comparing three styles of audio menus. One of these styles is the technique predominantly employed in interactive voice response (IVR) systems today. Two alternatives to this Standard technique were evaluated in this study. One of these alternatives was first proposed in Resnick and Virzi (1992), which they called Skip and Scan menus. This new style was hypothesized to be superior to Standard menus for intermediate users, but was expected to show limitations for one-time callers and expert users. The third menu alternative we evaluated combines elements of the Standard and Skip and Scan menus and was hypothesized to be superior in a broad range of usage conditions. Performance was measured over 36 tasks and two IVR applications. In all but the first few trials, the Skip and Scan menu style reported in Resnick and Virzi led to performance equal to or better than the other two menu styles. Standard menus showed a performance benefit for the first few trials of the first application only: this benefit was not present in the second application. There were no differences among the techniques in the trials simulating expert behavior.”
© All rights reserved Virzi et al. and/or Human Factors Society
Mrazek, Deborah, Cocklin, Tom, Schumacher, Robert, Virzi, Robert A. and Chalupnik, Kay (1991): Now that You Have a Usability Lab, How Do You Make It Effective?. In: Proceedings of the Human Factors Society 35th Annual Meeting 1991. pp. 666-667.
“Our presentation two years ago discussed how to design a Usability Lab. Now that you've done that, it's time to talk about how to use a Lab Effectively. Our hope is that this session will let you walk away with new ideas, practical tips, things to avoid and a better understanding of how to get the most out of the investment you have made in building a Usability Lab. Our panel is made up of five people who currently mange Usability Labs. Discussion topics range from objective setting and data collection methods to how well the usability lab is received by development teams. Each panel member will focus on one of these aspects. Our intent is to combine formal presentations with audience discussion. In order to do this, we ask that you be prepared to help list specific areas of interest at the beginning of the session so that presenters can address these issues. Any topics not covered during the formal presentations will be used as the discussion topics for the end of the session.”
© All rights reserved Mrazek et al. and/or Human Factors Society
Virzi, Robert A., Penn, Dick, Tullis, Thomas S. and Greene, Sharon L. (1990): The Uses of Prototyping in User Interface Design and Evaluation. In: D., Woods, and E., Roth, (eds.) Proceedings of the Human Factors Society 34th Annual Meeting 1990, Santa Monica, USA. pp. 264-266.
“This panel will explore the varied uses of prototyping in the user interface design process. We expect to show that there is no single thing called "user interface prototyping" and that the differences are, in many ways, greater than the similarities. Panelists have been chosen to represent a wide cross section of user interface design tasks. Collectively, members of the panel have experience in prototyping hardware and software, computer programs and telecommunications services, residential, business, and engineering applications, at various levels of fidelity, and in all parts of the design process. We expect to show how these factors all influence the way prototypes are used and that the designer must be careful in choosing the most appropriate prototyping methodology for his or her needs. Each panelist will begin by characterizing the portion of the design process that he or she will be talking about. This represents a major division in the way prototypes are used, both in the way that they are built and in the type of information sought by the designer. Prototypes used early in the design process (requirements analysis) tend to be of lower fidelity and are used to test preferences for design alternatives, while those used later in the design process (system specification) tend towards higher fidelity and are used to test usability. Each panelist will point out the strengths and weaknesses of his or her prototyping methodology. Each panelist will address the following points: * Appropriate uses of prototyping methodology (early vs. late in design process) * Characteristics of prototypes (platform, level of fidelity, etc.) * Information gathered from the prototypes (evaluate design preferences, measure performance, etc.) * Relative costs of the method (time to build, flexibility, etc.)”
© All rights reserved Virzi et al. and/or Human Factors Society
Virzi, Robert A. (1990): Streamlining the Design Process: Running Fewer Subjects. In: D., Woods, and E., Roth, (eds.) Proceedings of the Human Factors Society 34th Annual Meeting 1990, Santa Monica, USA. pp. 291-294.
“Recent attention has been focused on making user interface design less costly and more easily incorporated into the product development life cycle. This paper reports an experiment conducted to determine the minimum number of subjects required for a usability test. It replicates work done by Jakob Nielsen and extends it by incorporating problem importance into the curves relating the number of subjects used in an evaluation to the number of usability problems revealed. The basic findings are that (1) with between 4 and 5 subjects, 80% of the usability problems are detected and (2) that additional subjects are less and less likely to reveal new information. Moreover, the correlation between expert judgments of problem importance and likelihood of discovery is significant, suggesting that the most disruptive usability problems are found with the first few subjects. Ramifications for the practice of human factors are discussed as they relate to the type of usability test cycle the practitioner is employing, and the goals of the usability test.”
© All rights reserved Virzi and/or Human Factors Society
Virzi, Robert A. (1989): What Can You Learn from a Low-Fidelity Prototype?. In: Proceedings of the Human Factors Society 33rd Annual Meeting 1989. pp. 224-228.
“A case is made tor using low-fidelity prototypes early in the design phase of new services. The rationale for this is based upon (1) a model of how user interface designs progress and (2) a call to expediency. The design process is viewed as the successive application of constraints that serve to prune the space of all user interfaces. Some constraints are external (i.e., placed on the service by limits of technology or cost). Other constraints are derived by application of heuristic design principles. Even after these constraints have been applied, the design is still not fully constrained and the designer must make high-level design decisions. At these choice points, I propose that low-fidelity prototyping is an appropriate means of gathering design information as it is an expedient solution and may serve as a method of testing the central tendency of entire classes of user interfaces.”
© All rights reserved Virzi and/or Human Factors Society
Mason, Hardy, Mrazek, Deborah, Uyeda, Kathy, Virzi, Robert A. and Savage, Ricky (1989): The Practical Aspects of a Usability Lab. In: Proceedings of the Human Factors Society 33rd Annual Meeting 1989. pp. 630-631.
“This panel will explore the practical issues behind the scenes of a Usability Lab. The following topics will be discussed: how the labs are designed and built, including types of video equipment; what situations produce the need for a lab; the history of some of the labs; lessons learned in running a lab; and how Usability Labs will be utilized in the future. The panelists will be from different industries, testing different types of ideas, theories and products. Some of the Labs represented are several years old and some are just under construction. Usability lab testing is no longer restricted to academia and larger corporations. It is useful for many of us.”
© All rights reserved Mason et al. and/or Human Factors Society
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