Jolynn Pek received her Ph.D. in Quantitative Psychology from the University of North Carolina at Chapel Hill at the L. L. Thurstone Psychometric Laboratory in 2012. She was recently elected as a member of the Society for Multivariate Behavioral Research in 2017 and was awarded the Early Researcher Award by the Ontario Ministry of Research and Innovation in 2016. Her research interests are motivated by quantifying uncertainty inherent in results obtained from fitting models to data, especially latent variable models. Quantifying uncertainty is fundamental to understanding the limits of statistical results and ascertaining statistical conclusion validity.
There are many sources of uncertainty in statistical results. Uncertainty may be due to the presence of influential cases which can unduly affect parameter estimates, motivating the development of identification and diagnostic methods. Parameter estimates also carry uncertainty in the form of sampling variability which are communicated by confidence sets; a related but distinct aspect of parameter uncertainty is carried by fungible parameter estimates which are alternative descriptions of the data afforded by parameter values which are associated with a similar level of fit to the data compared to optimal estimates. Finally, the functional form linking constructs during the exploratory phase of research is uncertain, prompting the development of methods to flexibly recover unknown relationships. Dr. Pek has formalized and developed different approaches to quantify these various sources of uncertainty in terms of estimation, algorithms, measures, and graphical approaches.
Selected Methodological Papers
Pek, J., & Wu, H. (in press). Parameter uncertainty in structural equation models: Confidence sets and fungible estimates. Psychological Methods.
*Chalmers, R. P., Pek, J., & Liu, Y. (2017, June 8). Profile-likelihood confidence intervals in item response theory models. Multivariate Behavioral Research. Advance online publication. doi: 10.1080/00273171.2017.1329082
Pek, J., Wong, A. C. M., & *Wong, O. (2017). Confidence intervals for the mean of non-normal distribution: Transform of not transform. Open Journal of Statistics, 7, 405-421. doi: 10.4236/ojs.2017.73029.
Pek, J., & Flora, D. (2017, March 9). Reporting effect sizes in original psychological research: A discussion and tutorial. Psychological Methods. Advance online publication. doi: 10.1037/met0000126
*Flake, J. K., Pek, J., & Hehman, E. (2017). Construct validation in social and personality research: Current practice and recommendations. Social Psychological and Personality Science, 8, 370-378. doi: 10.1177/1948550617693063
Pek, J., *Chalmers, R. P, & Monette, G. (2016). On the relationship between confidence sets and exchangeable weights in multiple linear regression. Multivariate Behavioral Research, 51, 719-739. doi: 10.1080/00273171.2016.1225563
Pek, J., & Hoyle, R. H. (2016). On the (in)validity of tests of simple mediation: Threats and solutions. Social and Personality Psychology Compass, 10, 150-163. doi: 10.1111/spc3.12237
Pek, J., & Wu, H. (2015). Profile likelihood-based confidence intervals and regions for structural equation models. Psychometrika, 80, 1123-1145. doi: 10.1007/s11336-015-9461-1
Pek, J., *Chalmers, R. P., Kok, B. E. & Losardo, D. (2015). Visualizing confidence bands for semiparametrically estimated nonlinear relations among latent variables. Journal of Educational and Behavioral Statistics, 18, 537-553. doi: 10.3102/1076998615589129
Sterba, S. K., & Pek, J. (2012). Individual influence on model selection. Psychological Methods, 17, 582-599. doi: 10.1037/a0029253
Pek, J., & MacCallum, R. C. (2011). Sensitivity analysis in structural equation models: Cases and their influence. Multivariate Behavioral Research, 46, 202-228. doi: 10.1080/00273171.2011.561068
Selected Substantive Papers
Willoughby, M. W., Pek, J., Greenberg, M. & the Family Life Project Investigators (2012). Parent-reported attention deficit/hyperactivity symptomatology in preschool-aged children: Factor structure, developmental change, and early risk factors. Journal of Abnormal Child Psychology, 40, 1301-1312. doi: 10.1007/s10802-012-9641-8
Richman, L. S., Pek, J., Pascoe, E. & Bauer, D. J. (2010). The effects of perceived discrimination on ambulatory blood pressure and affective responses to interpersonal stress modeled over 24-hours. Health Psychology, 29, 403-411. doi: 10.1037/a0019045
Fredickson, B. L., Cohn, M. A., Coffey, K., Pek, J., & Finkel, S. M. (2008). Positive emotions induced through meditation build consequential personal resources. Journal of Personality and Social Psychology, 95, 1045-1062. doi: 10.1037/a0013262
Bishop, G. D., Ngau, F., & Pek, J. (2008). Domain specific assessment of anger expression and ambulatory blood pressure. Personality and Individual Differences, 44, 1726-1737. doi: 10.1016/j.paid.2008.01.024
Richman, L. S., Bennett, G, Pek, J., Siegler, I., & Williams, R. B. Jr. (2007). Discrimination, dispositions and cardiovascular responses to stress. Health Psychology, 26, 675-683. doi: 10.1037/0278-6188.8.131.525
*Student co-author during time of research conducted.
**Postdoctoral fellow co-author during time of research conducted.