Research / 1999 to 2013 / 9 publications
Measurement, and whether you can believe it
Three research lines, all about the same thing: does this instrument actually measure what it claims to measure? Sleep and shiftwork at UConn, visual cognition through the dissertation, then applied usability measurement at consumer scale. Twenty-six years later that question is still the one I ask first, whether the instrument is a scale, a survey, or a model.
M.A. thesis
UConn, 2000 · public, full textAssessing Sleep Quality in Commercial Maritime Crewmembers: Is the Sleep Disturbance Scale a Valid Measure?
A psychometric validation study, not a sleep study. Earlier work had assembled four self-report items into a provisional Sleep Disturbance Scale and found no relationship between it and sleep length in maritime crews. That null had two readings: maritime duty does not hurt sleep quality, or the scale does not measure sleep quality. This thesis exists to decide which.
The method was a validity evidence chain. Convergent validity against personality and sleep-habit measures. Discriminant validity against things the scale should not track. Criterion validity against actual sleep length. Then a structural equation model fit against an established theoretical model.
Verdict: the scale is valid in this sample, so the original null is real. Maritime duty shortened sleep without degrading sleep quality. Four of ten predictions failed outright and the write-up says so plainly.
- Degree
- M.A., 2000
- Major advisor
- Donald I. Tepas
- Committee
- David A. Kenny
- Committee
- Marc Mandler
- Sample
- 116 crew, 8 ships
- Data partner
- U.S. Coast Guard
- Model fit
- CFI 1.000
- RMSEA
- .000
The mediation test used Baron and Kenny (1986). David Kenny sat on the committee and signed the thesis.
Three habits from this document are still in everything I do. Reliability is treated as necessary and nowhere near sufficient: the scale had a good alpha in two samples and I still spent thirty-three pages arguing that this proves nothing about validity. Response bias in high-stakes settings is named directly, because people whose livelihood depends on being fit will not self-report impairment. And the future-research section argues that every correlation in the study might be an artifact of everything being a self-report Likert item, and calls for a multitrait-multimethod matrix. That is the argument for simulation-based measurement over questionnaires, made twenty-six years early.
Doctoral dissertation
UConn, 2002Development of Cognitive Styles and Strategies in the Visual Discrimination of Computer Displayed Graphics: Task Characteristics, Training and Design
Ph.D. in Industrial/Organizational Psychology, concentrating in human factors, judgment and decision making, data visualization, and UX research and design. The dissertation asks how people with different cognitive styles learn to read serially presented graphics, and what that means for how you design and train against a display.
Four of the nine publications below are the published spine of this work, run with R. James Holzworth and Young Woo Sohn.
- Degree
- Ph.D., 2002
- Field
- I/O Psychology
- Institution
- UConn
- Dissertation ID
- AAI3062095
Peer-reviewed publications
9 · from ORCID, 2026-08-13Nine publications across three research lines. Sleep and shiftwork, two publications in 1999 and 2000. Visual cognition, four publications from 2001 to 2004. Applied usability, three publications, two in 2008 and one in 2013. No publications between 2005 and 2007, or between 2009 and 2012. The list below is the complete record.
Howarth, H. D., Pratt, J. H., & Tepas, D. I. (1999). Do maritime crew members have sleep disturbances? International Journal of Occupational and Environmental Health, 5(2), 95-100.
Tepas, D. I., Pratt, J. H., & Howarth, H. D. (2000). Inter-individual vs intra-individual differences: An important distinction for shiftwork research? In S. Hornberger, P. Knauth, G. Costa, & S. Folkard (Eds.), Shiftwork in the 21st Century (pp. 273-279). Frankfurt am Main: Peter Lang.
Pratt, J. H., & Sohn, Y. W. (2001). Individual difference effects on training and transfer of visual processing strategy. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 45(13), 926-930.
Kramer, E., Pratt, J. H., & Sohn, Y. W. (2002). Task context and individual difference effects on skill acquisition of visual processing strategy. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 46(12), 973-977.
Kramer, E., Holzworth, R. J., Sohn, Y. W., Pratt, J. H., & Nelson, C. (2003). Serial presentation of computer graphics: Training effects and strategy development for analytic and holistic cognitive styles. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 47(9), 1058 to 1062.
Pratt, E. K., & Pratt, J. H. (2004). Training and individual difference effects on the ability to visually discriminate serially presented graphics: Short term memory capacity in analytic and holistic cognitive styles. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 48(11), 1208 to 1212.
Sullivan, M., Pratt, J., & Kortum, P. (2008). Practical issues in subjective video quality evaluation: human factors vs. psychophysical image quality evaluation. In Proceedings of the 1st International Conference on Designing Interactive User Experiences for TV and Video (UXTV '08) (pp. 1-4). ACM.
Winters, J., Belz, S., & Pratt, J. (2008). HSI for consumer products: Does the shoe fit? INSIGHT, 11(2), 31-34.
Bangor, A., Joseph, K., Sweeney-Dillon, M., Stettler, G., & Pratt, J. (2013). Using the SUS to help demonstrate usability's value to business goals. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 57(1), 202-205.