Sangdon Lim

I am a psychometrician specializing in computerized adaptive testing (CAT). I have publications in top-notch journals including Psychological Methods and Psychometrika, and have worked on multiple industry-sponsored CAT projects. I also happen to be a cat person.

Education

• PhD   Educational Psychology, University of Texas at Austin2023
• MA    Psychology, Sungkyunkwan University2017

Experience

• Psychometrician, Cambium Assessment2023.09 - current
• Graduate Research Assistant, University of Texas at Austin2022.09 - 2023.08
  • Worked as the main programmer of two R packages for performing adaptive test assembly simulations. These were contracted products for operational use.
  • Presented technical information to psychometrician and non-psychometrician audiences.
  • Caught where technical specifications were incomplete; discussed these with contracting organizations.
  • Led workshops in national conferences, both in-person and remotely.
  • Worked on adding features to R packages to facilitate studies led by colleagues.
  • Aided extensively in computer programming topics, such as making functions run faster, helping colleagues to learn version control and on general debugging, and making code easier to understand.
• Fellowship recipient, University of Texas at Austin2021.09 - 2022.08
  • This came with on-campus work restriction.
• Graduate Research Assistant, University of Texas at Austin2019.01 - 2021.08
  • Worked as the main programmer of three R packages: TestDesign, PROsetta, and maat. Topics included performing scale linking between instruments using item response theory and fixed-parameter calibration technique, performing adaptive test assembly simulations, and adding features to summarize item pool and test properties. These packages are publicly available from the CRAN repository.
  • Wrote package function help pages, tutorials, user guides, and technical documentations.
  • Wrote automated codetests for quality checks for development purposes.
• Intern, Creative Measurement Solutions2020.06 - 2020.08
  • Worked on front-end development and quality assurance of a Shiny application, for a new standard setting method (embedded standard setting) for operational testing programs.
  • Wrote a user guide and presented a tutorial.
• Graduate Research Assistant, University of Texas at Austin2019.01 - 2020.05
  • Worked on secondary analysis of Women’s Health Initiative (WHI) data using Mplus and SPSS.
  • Also worked on data organization and management of a large dataset with over 80k rows.
• Graduate Research Assistant, Sungkyunkwan University2015 - 2016
  • Participated in developing a psychometrics-based credit rating system for a fintech startup.
  • Worked on fitting Thurstonian IRT models to ipsative response data using Mplus.
  • Presented the technical process of parameter estimation to non-statisticians using Excel solver.
• Teaching Assistant, Sungkyunkwan University2015 Fall, 2016 Fall
  • Course title: Statistical Analysis in Psychology

Publications

• Gianopulos, G., Lee, J., Lim, S., Niu, L., Lee, S., & Choi, S. W. (in press). The impact of item pool size and item pool distribution on student ability estimates for a hybrid interim-summative CAT. Journal of Computerized Adaptive Testing.
• Lee, J., Lim, S., Schneider, M. C., Gianopulos, G., Niu, L., Lee, S., & Choi, S. W. (in press). The impact of item bank transition rules on student ability estimates and achievement level classifications. Journal of Computerized Adaptive Testing.
• Lim, S., & Choi, S. W. (2024). Item exposure and utilization control methods for optimal test assembly. Behaviormetrika, 51, 125-156. doi
• Lim, S. (2023). Domain score estimation in adaptive test assembly for single-subject multiple-domain content. [Doctoral dissertation, University of Texas at Austin]. Texas ScholarWorks. doi
• Choi, S. W., Lim, S., Niu, L., Lee, S., Schneider, C. M., Lee, J., & Gianopulos, G. J. (2022). maat: an R package for multiple administrations adaptive testing. Applied Psychological Measurement, 46(1), 73-74. doi
• Choi, S. W., & Lim, S. (2022). Adaptive test assembly with a mix of set-based and discrete items. Behaviormetrika, 49(2), 231-254. doi materials (invited paper)
• Choi, S. W., Lim, S., & van der Linden, W. J. (2022). TestDesign: an optimal test design approach to constructing fixed and adaptive tests in R. Behaviormetrika, 49(2), 191-229. doi (invited paper)
• Choi, S. W., Lim, S., Schalet, B. D., Kaat, A. J., & Cella, D. (2021). PROsetta: an R package for linking patient-reported outcome measures. Applied Psychological Measurement, 45(5), 386-388. doi
• Schalet, B. D., Lim, S., Cella, D., & Choi, S. W. (2021). Linking scores with patient-reported health outcome instruments: a validation study and comparison of three linking methods. Psychometrika, 86(3), 717-746. doi
• Holahan, C. J., Holahan, C. K., Lim, S., Powers, D. A., & North, R. J. (2022). Living with a smoker and physical inactivity across eight years in high-risk medical patients. Behavioral Medicine, 48(4), 284-293. doi
• Holahan, C. J., Holahan, C. K., Lim, S., & Powers, D. A. (2021). Living with a smoker and multiple health risk behaviors. Annals of Behavioral Medicine, 55(4), 287-297. doi
• Lim, S. (2020). Review: A course in item response theory and modeling with Stata, and Using R for item response theory model applications. Structural Equation Modeling: A Multidisciplinary Journal, 27(4), 657-659. doi
• Holahan, C. J., Holahan, C. K., Lim, S., & Powers, D. A. (2020). Living with a smoker, health risk behaviors, and adiposity: an analysis with middle-aged and older women. Journal of Behavioral Medicine, 43(5), 850-858. doi
• Lim, S., & Jahng, S. (2019). Determining the number of factors using parallel analysis and its recent variants. Psychological Methods, 24(4), 452-467. doi materials
• Lim, S., & Jahng, S. (2017). 요인 개수 결정을 위한 평행분석의 정확성 평가 [Evaluating the accuracy of parallel analysis for determining the number of common factors]. Korean Journal of Psychology: General, 36(4), 441-475. doi link

Presentations

• Chen, J., Lim, S., & Schneider, M. C. (2024, April 14). Embedded standard setting efficacy under different item alignment and empirical difficulty conditions. Alignment and standard setting: interrogating methodologies in support of instructional utility [Coordinated paper session]. Paper presented at the annual meeting of the National Council on Measurement in Education, Philadelphia, PA.
• Choi, S. W., & Lim, S. (2024, April 11). Optimal test design approach to fixed and adaptive test construction using R. Training session at the annual meeting of the National Council on Measurement in Education, Philadelphia, PA.
• Lim, S., Jiang, T., & Schneider, M. C. (2024, March 22). Investigating the adoption of marginal reliability for use in three operational testing programs. Paper presented at the annual meeting of Texas Universities’ Educational Statistics and Psychometrics (TUESAP) Conference, Denton, TX.
• Lim, S., & Choi, S. W. (2023, April 15). Domain score estimation in adaptive testing for single-subject multiple-domain content. Computer adaptive testing models and estimation [Paper session]. Paper presented at the annual meeting of the National Council on Measurement in Education, Chicago, IL.
• Choi, S. W., & Lim, S. (2023, March 28). Optimal test design approach to fixed and adaptive test construction using R. Training session at the annual meeting of the National Council on Measurement in Education, Chicago, IL.
• Gianopulos, G., Lee, J., Lim, S., Niu, L., Lee, S., & Choi, S. W. (2022, April 22). Impact of item pool size and distribution on a TY system. Considerations in the design of through year computer adaptive assessments [Coordinated paper session]. Paper presented at the annual meeting of the National Council on Measurement in Education, San Diego, CA.
• Lee, J., Schneider, C., Gianopulos, G., Niu, L., Lee, S., Lim, S., & Choi, S. W. (2022, April 22). Impact of test routing rules on theta estimates and achievement level classifications. Considerations in the design of through year computer adaptive assessments [Coordinated paper session]. Paper presented at the annual meeting of the National Council on Measurement in Education, San Diego, CA.
• Choi, S. W., & Lim, S. (2022, April 8). Optimal test design approach to fixed and adaptive test construction using R. Training session at the annual meeting of the National Council on Measurement in Education, San Diego, CA.
• Choi, S. W., & Lim, S. (2021, June 8). Optimal test design approach to fixed and adaptive test construction using R. Training session at the annual meeting of the National Council on Measurement in Education.
• Choi, S. W., & Lim, S. (2021, January 29). Adaptive testing with complex test specifications. Advanced technologies for adaptive testing [Symposium]. 2nd International Workshop on Data Science, Tokyo, Japan. url (Invited presentation)
• Choi, S. W., Lim, S., & van der Linden, W. J. (2021, January 29). TestDesign: an optimal test design approach to constructing fixed and adaptive tests in R. Advanced technologies for adaptive testing [Symposium]. 2nd International Workshop on Data Science, Tokyo, Japan. url (Invited presentation)
• Holahan, C. K., Holahan, C. J., Lim, S., Chen, Y. T., & Powers, D. A. (2019, November). Sociodemographic disadvantage, living with a smoker, and obesity in middle-aged and older women. Poster session presented at the annual meeting of the Gerontological Society of America, Austin, TX.
• Cheong, J., Jung, S., & Lim, S. (2018, May). Two-part modeling approach to mediation analysis for semi-continuous outcomes. Poster session presented at the annual convention of the Society for Prevention Research, Washington, DC.
• Lim, S. (2017, May). 고유값 감쇠에 따른 평행분석 및 대안적 요인수 추정 알고리즘의 정확성 비교 [Accuracy of parallel analysis and its alternatives across eigenvalue attenuation]. Paper presented at the meeting of the Korean Society of Psychological Measurement and Assessment, Seoul, Korea.
• Lim, S. (2016, November). 요인상관과 소요인 유무에 따른 평행분석을 이용한 요인 수 추정의 정확성 [Accuracy of parallel analysis across factor correlation and weak factor presence]. Poster session presented at the meeting of the Korean Society of Psychological Measurement and Assessment, Seoul, Korea.

Contributions

• 2023: Invited and participated as a reviewer for a paper on Educational and Psychological Measurement.

Scholarships

• 2022: Professional Development Award, Department of Educational Psychology, University of Texas at Austin.
• 2021: Graduate School Continuing Fellowship, University of Texas at Austin. (work restriction from 2021F to 2022Su)
• 2020: H. Paul and Decourcy Kelley Endowed Fellowship in Psychometrics, University of Texas at Austin.
• 2020: Reid Educational Psychology Award, Department of Educational Psychology, University of Texas at Austin.
• 2019: Bascombe Royall and Frances Fallon Fuller Scholarship, University of Texas at Austin.
• 2018: Graduate School Recruitment Fellowship, Department of Educational Psychology, University of Texas at Austin.
• 2017: Travel Grant, BK21 PLUS, Ministry of Education, South Korea.
• 2016: Scholarship, BK21 PLUS, Ministry of Education, South Korea.
• 2015: Graduate School Recruitment Fellowship, Department of Psychology, Sungkyunkwan University.