About

Professor Philip Kortum is a faculty member at Rice University in the Department of Psychological Sciences. He has over 15 years of experience in industry, where he engaged in hands-on human factors and applied research and development. His work focuses on human factors and engineering psychology, and he aims to share his practical knowledge with students to enhance their understanding of these fields. Kortum has authored books such as 'HCI Beyond the GUI' and 'Usability Assessment,' which reflect his expertise in non-graphical interfaces and usability testing. His laboratories are located on the Rice University campus in Houston, Texas.

Research topics

• Computer Science
• Computer Security
• Political Science
• Psychology
• Business
• Law
• Human–computer interaction
• Natural Language Processing
• Applied psychology
• Engineering
• Geography
• Statistics
• Social psychology
• Medicine
• Linguistics
• Mathematics
• Public relations
• Clinical psychology
• Internet privacy
• Developmental psychology

Selected publications

• System Usability Measured Over Time: An Exploratory Descriptive Study

  International Journal of Human-Computer Interaction · 2026-02-18

  article1st authorCorresponding
  PublisherDOI

• Check it to Protect it: Understanding the Behaviors Driving Ballot Verification

  Proceedings of the Human Factors and Ergonomics Society Annual Meeting · 2025-09-01

  articleOpen access

  This study sought to understand the factors influencing voters to verify their paper ballots produced by an electronic Ballot Marking Device (BMD). To tackle this question, 60 undergraduate students from Rice University participated in mock elections where their votes on the electronic BMD displayed their selections accurately, but then a subset of their votes on the printed ballots were altered. After the system printed the paper ballot, two user interface (UI) interventions aimed at improving ballot verification rates were displayed in the following sequence: (1) a digital-based prompt instructing voters to “Carefully check your printed ballot. Take your time. Make sure everything is correct” and asked the question, “Are your printed selections correct?” requiring an on-screen response of “Yes” or “No,” and (2) a paper-based prompt requiring voters to handscribe their signature, a checkmark, or a sentence on the paper ballot. The results revealed that the paper-based intervention did not influence ballot verification performance, as all participants who detected at least one anomaly destroyed their compromised ballots after encountering the digital-based intervention. The overall detection rate on the digital-based intervention was high, with 88% of voters detecting changes in their ballots, suggesting that this ballot verification intervention was an effective countermeasure to encourage voters to check their paper ballots. The findings from this study can inform voting system design guidelines that motivate voters to independently audit their own ballot for anomalies.

  PublisherOA PDFDOI

• From Childhood to Independence: A Needs Assessment for mHealth Interventions for Women with Autism and Their Caregivers

  Proceedings of the Human Factors and Ergonomics Society Annual Meeting · 2025-09-01

  articleOpen accessSenior author

  The transition to adulthood is a pivotal life stage for women diagnosed with Autism Spectrum Disorder (ASD) that is marked by challenges which include, but are not limited to, the transition from pediatric to adult healthcare, securing employment and higher education, and navigating romantic relationships and sexuality. Caregivers also play a very important role during this period, but some suffer from burnout, stress, and a lack of adequate resources to provide proper care. There is a lack of existing interventions and research focused on young female adults with ASD and their caregivers. To address this disparity and provide effective support, creating tailored interventions for these specific populations is essential. In this work, we investigated the needs of young women with ASD and their caregivers through semi-structured interviews with eleven participants, three of which were subject matter experts and eight were caregivers. The thematic analysis revealed four key barriers faced by women with ASD and their caregivers: (1) transitioning to adult healthcare, (2) navigating romantic relationships and sexuality, (3) lack of guidance on employment, higher education, and independent living options, and (4) burnout and well-being among caregivers. The findings from this needs assessment aim to guide the design of a targeted mHealth intervention for women with ASD and their caregivers.

  PublisherOA PDFDOI

• Stop Hiding My Controls: Hidden Interface Controls Are Affecting Usability

  interactions · 2025-06-20

  articleOpen access1st authorCorresponding
  PublisherOA PDFDOI

• Explaining How to Interpret a Usability Survey May Enhance Internal Reliability Without Negatively Influencing Responses

  Proceedings of the Human Factors and Ergonomics Society Annual Meeting · 2025-09-01

  articleOpen accessSenior author

  A great challenge to employing questionnaires is ensuring that respondents understand them. One possible strategy is to explain the meaning of items but there is a risk in biasing respondents’ answers. In this study, we assessed how explaining the meaning of items to respondents might affect their responses and the validity/reliability of the Positive System Usability Scale (PSUS). We employed straightforward, general explanations that we felt matched the intended meaning of the items. We found a statistically significant difference between the Explanations and No Explanations groups, but we judged this effect as not practically significant. We found the validity and reliability of the questionnaires from both groups to be acceptable. Finally, the reliability of the PSUS questionnaires given to the Explanations group was systematically higher than the No Explanations group, suggesting that correctly explaining items may enhance the reliability of questionnaires, perhaps by enhancing respondents’ understanding of the questionnaire items.

  PublisherOA PDFDOI

• Emergence of Paper-Digital Systems: A Usability Evaluation of Single-Page Versus Multipage Digital Instructions in a Ballot Mailing Task

  Proceedings of the Human Factors and Ergonomics Society Annual Meeting · 2024-08-13

  articleOpen access

  Findings from previous research that assessed the usability of single-page and multipage digital interfaces in purely digital interactions indicated that the single-page format is more efficient than its multipage counterpart. This research expands on previous work by applying the findings from these digital-only interactions to a paper-digital interaction. Specifically, this study assessed the usability of single-page and multipage instructional interfaces to guide voters through the paper-based ballot mailing process embedded in the prototype of an electronic voting system designed for overseas military voters. A detailed classification of errors and requests for assistance revealed that the multipage format had fewer occurrences of both than the single-page format. Statistical analyses revealed no statistically significant differences between the single-page and multipage interfaces in efficiency, contrary to previous research, as well as no differences in effectiveness, satisfaction, and workload. To conclude, we provide arguments in favor of utilizing the multipage format for the digital display of the ballot mailing instructions on electronic voting systems moving forward. These findings can reveal best practices for the design of digital instructions in emerging paper-digital systems.

  PublisherOA PDFDOI

• Viability of Proxy Users for Usability Testing of Neonatal Devices for Use in Sub-Saharan Africa: A Qualitative Analysis of use Errors

  Proceedings of the International Symposium on Human Factors and Ergonomics in Health Care · 2024-06-01

  articleSenior author

  Medical devices designed for use in low-resource settings require unique and thoughtful design considerations to facilitate successful implementation and adoption. Usability testing is critical for good design but conducting research in international locations with intended target users is challenging and costly. Proxy user groups have been proposed as a reasonable solution when travel is impractical or wholly restricted, as it was during the Covid-19 pandemic. This study explored the viability of utilizing a proxy user group in Houston, TX, USA, to represent nurses in Blantyre, Malawi, to assess the usability of neonatal medical devices designed for use in sub-Saharan Africa. Seven devices were tested with 13 clinicians in Houston, Texas, and 17 clinicians in Blantyre, Malawi. Participants in Houston were carefully selected to mirror Malawi's expected demographics, particularly educational background and years of experience. This analysis compared the rates and types of use errors that occurred within each group. Results indicated that the Houston nurses recruited were an insufficient proxy to represent Malawian nurses in usability studies, with only 53.7% of errors observed in both groups. Furthermore, common errors identified tended to be more severe in Blantyre than in Houston, indicating that caution should be exercised when relying on proxy users. Future work should explore these observed differences further, and larger sample sizes should be utilized to assess the viability of a proxy group. Although proxy usability testing can be advantageous, testing with target users remains the gold standard.

  PublisherDOI

• A Tension: Fortifying Usability While Safeguarding Voter Independence in Military Voting Solutions

  Proceedings of the Human Factors and Ergonomics Society Annual Meeting · 2024-08-12

  articleOpen accessSenior author

  Absentee voting presents a unique challenge for U.S. uniformed service members, as they often struggle to request and return absentee ballots while deployed, sometimes stationed far from their registered voting area. This research evaluates the usability of a proposed absentee voting system for military voters, which allows instant ballot requests and enables voters to verify their own votes, focusing on whether the user interface supports effective use among military personnel. Our evaluation revealed that military voters frequently relied on external assistance to navigate the electronic voting system, revealing opportunities for its improvement and design recommendations to facilitate absentee voting for U.S. military personnel.

  PublisherOA PDFDOI

• A Call to Arms for American Democracy

  Ergonomics in Design The Quarterly of Human Factors Applications · 2024-11-22

  article

  Free, fair, and secure elections are the foundation of a democracy. However, the idea of voting is simple, whereas its execution is complex. There are over 3000 counties in the United States, representing 10,000 election jurisdictions with varying laws, demographics, logistics, and levels of technology integration. There are numerous open challenges that Human Factors expertise can directly translate, such as the design to maximize accessibility and security, improve poll worker training, and minimize errors. The time is now to get involved in this dynamic and rewarding applied research space, as ensuring election integrity has never been more critical.

  PublisherDOI

• A Formative Usability Study Evaluating a Decision Aid for Caregivers of Incapacitated Patients

  Proceedings of the Human Factors and Ergonomics Society Annual Meeting · 2024-08-13

  articleOpen accessSenior author

  Families making medical decisions for an incapacitated loved one need to process medical information for various care pathways while balancing different perspectives and experiencing distress. A decision aid tool to help family members make medical decisions on the patient’s behalf should be easy to use and not create additional burdens. A formative usability study with high, medium, and low verbosity versions of an initial decision aid was conducted with university students before clinical testing. The results showed no significant differences in usability metrics between different verbosity levels, but the qualitative findings indicated areas of improvement in the organization of information that could lead to improved usability of the decision aid. While the findings are limited due to the study being void of some of the burdens families face in true clinical situations, the study allowed us to identify numerous usability issues before testing with target users.

  PublisherOA PDFDOI

Recent grants

• Usability of Voting Systems

  NSF · $170k · 2010–2013

Frequent coauthors

• Claudia Ziegler Acemyan

  Rice University

  34 shared

• Michael D. Byrne

  27 shared

• Chad C. Tossell

  United States Air Force Academy

  22 shared

• S. Camille Peres

  United States Nuclear Regulatory Commission

  22 shared

• Frederick L. Oswald

  Rice University

  21 shared

• Ahmad Rahmati

  Imam Hossein University

  17 shared

• Clayton Shepard

  Rice University

  17 shared

• Lin Zhong

  Yale University

  17 shared