A mathematical model of the finding of usability problems

Nielsen, Jakob; Landauer, Thomas K.

doi:10.1145/169059.169166

Cited by 1,252 publications

(830 citation statements)

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“…Residents were screened, and those who fit the inclusion and exclusion criteria were enrolled. We targeted five total residents for testing, with the number selected based on the recommendation that testing with five users can identify 80 percent of the usability issues [41]. Resolving issues identified from testing with five users allows product developers to move quickly to a new iteration of the design for subsequent testing.…”

Section: Recruitmentmentioning

confidence: 99%

Usability testing of multimodal feedback interface and simulated collision-avoidance power wheelchair for long-term-care home residents with cognitive impairments

Wang¹,

Mihailidis²,

Dutta³

et al. 2011

JRRD

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Abstract-Many older adults in long-term-care homes have complex physical and cognitive impairments and have difficulty propelling manual wheelchairs. Power wheelchair use is restricted owing to safety concerns. Power wheelchairs with collisionavoidance features are being developed to enable safe and independent mobility; however, a paucity of information exists on interface features to help users navigate away from obstacles. We developed a system combining an interface with auditory, visual, and haptic feedback and a simulated collision-avoidance power wheelchair. This device allowed the investigator to stop movement of the power wheelchair when users approached obstacles and to deliver feedback to help them navigate. Five long-termcare home residents with mild or moderate cognitive impairments evaluated device usability, which included effectiveness, efficiency, and user satisfaction. Each resident used the device for six 1 h sessions. Observations, feedback interviews, and outcome questionnaires were completed during and after the sessions. We found the device effective in enabling residents to achieve basic driving tasks and self-identified indoor mobility goals. Furthermore, residents perceived workload to be low and were satisfied with the device. Residents also felt that the feedback was useful to help them navigate away from obstacles.

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Section: Recruitmentmentioning

confidence: 99%

Usability testing of multimodal feedback interface and simulated collision-avoidance power wheelchair for long-term-care home residents with cognitive impairments

Wang¹,

Mihailidis²,

Dutta³

et al. 2011

JRRD

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“…Usability testing generally involves measuring how well test subjects respond in four areas: time, accuracy, recall, and emotional response. The mathematical model that Nielsen and Landauer [6] established for identifying usability problems indicates that five users can identify 85% of a system's usability problems, while at least 15 users are required to adequately identify most of a design's usability problems.…”

Section: Introductionmentioning

confidence: 99%

Iterative refinement of a tailored system for self-care management of depressive symptoms in people living with HIV/AIDS through heuristic evaluation and end user testing

Lai

2007

International Journal of Medical Informatics

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Background: HIV TIDES -tailored interventions for self-care management of depressive symptoms for people living with HIV/AIDS (PLWHA) -provides assessment of depression and tailored education on self-care strategies to decrease the risk of developing clinical depressive disorders. The iterative refinement of the prototype is an important process during system development to ensure that the design of the system is easy to use and useful. Methods:The heuristic evaluation and usability testing methodologies were used to guide the iteration of the HIV TIDES. Results:The system's compliance with the majority of usability concepts and current standards was confirmed by three experts on human-computer interaction in the heuristic evaluation. However, a number of usability problems were identified. Refinements were made based on experts' recommendations prior to the usability testing. The usability testing included six PLWHA with various levels of computer experience. Data from this iterative testing informed the refinement of key pages and the development of new features. Conclusions:The final version of HIV TIDES consists of 73 messages. The average readability level of the messages is 6.0 based on the Flesch-Kincaid Grade Level and the average word count is 103.Keywords depressive symptom; HIV/AIDS; tailoring; self-care management; heuristic evaluation; usability testing Summary Points:What was known before the study?• Usability evaluation is a necessary step for improving system ease of use and usefulness during the system development process.• Heuristic evaluation with usability experts provides efficient feedback at a relatively low cost in the early stages of system development.Correspondent: Tsai-Ya Lai Mail Code 6 630 West 168 th Street New York, NY 10032 Office: 212−305−6451 E-mail: TL105@columbia.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. • Usability testing explores sustainability problems from the perspective of system end users. NIH Public AccessAuthor Manuscript Int J Med Inform. Author manuscript; available in PMC 2008 October 1.What has the study added to the body of knowledge?• In order to evaluate a tailoring system, testing scenarios should be carefully designed to reflect all functions that were included in the system. • Discussion with experts at the end of the heuristic evaluation session is a critical step prioritizing the usability problems and exploring possible solutions for system iterations.• The involvement of PLWHA with various computer backgrounds in the usability testing enhances the likelihood that the system fits the needs of a...

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“…A total of 12 unique participants were recruited for the study. Eight participants were recruited for the first iteration of testing and four for the second iteration [32][33][34]. Practitioners were eligible if they were currently a practicing physician or clinical pharmacist with training or an active practice in the fields of cardiology, anticoagulation, internal medicine or ambulatory care.…”

Section: Participant Selection and Recruitmentmentioning

confidence: 99%

Iterative Development and Evaluation of a Pharmacogenomic-Guided Clinical Decision Support System for Warfarin Dosing

Melton¹,

Zillich²,

Saleem³

et al. 2016

Appl Clin Inform

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SummaryObjective: Pharmacogenomic-guided dosing has the potential to improve patient outcomes but its implementation has been met with clinical challenges. Our objective was to develop and evaluate a clinical decision support system (CDSS) for pharmacogenomic-guided warfarin dosing designed for physicians and pharmacists. Methods: Twelve physicians and pharmacists completed 6 prescribing tasks using simulated patient scenarios in two iterations (development and validation phases) of a newly developed pharmacogenomic-driven CDSS prototype. For each scenario, usability was measured via efficiency, recorded as time to task completion, and participants' perceived satisfaction which were compared using Kruskal-Wallis and Mann Whitney U tests, respectively. Debrief interviews were conducted and qualitatively analyzed. Usability findings from the first (i.e. development) iteration were incorporated into the CDSS design for the second (i.e. validation) iteration. Results: During the CDSS validation iteration, participants took more time to complete tasks with a median (IQR) of 183 (124-247) seconds versus 101 (73.5-197) seconds in the development iteration (p=0.01). This increase in time on task was due to the increase in time spent in the CDSS corresponding to several design changes. Efficiency differences that were observed between pharmacists and physicians in the development iteration were eliminated in the validation iteration. The increased use of the CDSS corresponded to a greater acceptance of CDSS recommended doses in the validation iteration (4% in the first iteration vs. 37.5% in the second iteration, p<0.001). Overall satisfaction did not change statistically between the iterations but the qualitative analysis revealed greater trust in the second prototype. Conclusions: A pharmacogenomic-guided CDSS has been developed using warfarin as the test drug. The final CDSS prototype was trusted by prescribers and significantly increased the time using the tool and acceptance of the recommended doses. This study is an important step toward incorporating pharmacogenomics into CDSS design for clinical testing. Research ArticleBL Background And SignificancePersonalized medicine is an emerging field with the fundamental objective to predict a patient's response in order to individualize drug therapy for improved medication effectiveness and safety. Pharmacogenomic-guided drug therapy is at the forefront of personalized medicine with over 150 United States Food and Drug Administration (FDA) approved drug labels incorporating pharmacogenomic information.[1] Nonetheless, the translation of pharmacogenomic testing into routine clinical practice has been slow due to several obstacles towards its implementation [2][3][4]. Currently, the routine use of clinical pharmacogenomics is limited to centers with resources to overcome these obstacles [5][6][7][8][9].A major obstacle in the implementation of clinical pharmacogenomics is the rapid pace that science has identified genetic polymorphisms that can predict drug response. Th...

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A mathematical model of the finding of usability problems

Cited by 1,252 publications

References 17 publications

Usability testing of multimodal feedback interface and simulated collision-avoidance power wheelchair for long-term-care home residents with cognitive impairments

Usability testing of multimodal feedback interface and simulated collision-avoidance power wheelchair for long-term-care home residents with cognitive impairments

Iterative refinement of a tailored system for self-care management of depressive symptoms in people living with HIV/AIDS through heuristic evaluation and end user testing

Iterative Development and Evaluation of a Pharmacogenomic-Guided Clinical Decision Support System for Warfarin Dosing

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