CV

Work & Research Experience

2025 - present : Senior Psychometrician
- Cambium Assessment
2021 - 2025 : Associate Research Scientist
- Pearson
2021 - 2021 : Data Science Intern
- Corgee
2018 - 2021 : Research Assistant
- The University of Iowa
2019 - 2020 : Preceptorship
- ACTNext
  - Developed an innovative item response model through extensive derivations and implemented it in R via optimization algorithms.
  - Evaluated model performance on both simulated and large-scale operational data.
June 2020 - July 2020 : Psychometric Intern
- Alpine Testing Solutions
  - Validated a newly developed statistical software.
  - Investigated literatures on cheating detection.
  - Presented findings and recommendations to the psychometric team.
2017 - 2018: Statistics Tutor
- The University of Iowa
  - Articulated statistical concepts and cleared confusions and misunderstandings for 10+ clients
  - Reviewed and revised SAS/R codes to improve computing accuracy and efficiency
2015 - 2016: Lecturer
- University of Pittsburgh
  - Developed course syllabus, guides, materials.
  - Wrote and assembled quizzes/assignments/exams and designed analytic grading rubrics to diagnose students’ performance.
  - Gave constructive feedback.

Skills

Computing: R/SAS/SPSS/Python, Winsteps/FlexMIRT, SQL, Mplus, Qualtrics, Windows, Unix
Statistics: regression, generalized linear models, categorial/longitudinal models, experimental design, Bayesian modeling, predictive models, clustering
Psychometrics: item response theory, classical test theory, factor analysis, structural equation modeling, generalizability theory, equating, diagnostic models

Education

Ph.D in Educational Measurement and Statistics, The University of Iowa
- Minor: Mathematical Statistics
M.S in Biostatistics, The University of Iowa
B.A & M.A in Classical Chinese Literature, Nanjing University

Training & Certificates

Demystify Amazon Web Services (AWS): Cloud Computing, and Psychometric Applications, Annual Meeting of National Council on Measurement in Education (2023), Chicago, IL
Addressing the Data Challenges of Next-generation Assessments: Data Science Upskilling for Psychometricians, Annual Meeting of National Council on Measurement in Education (2022), virtual
Using Stan for Bayesian Psychometric Modeling, Annual Meeting of National Council on Measurement in Education (2021), virtual
NAEP Data Training Workshop (2020), Arlington, VA
SAS Certified Base Programmers for SAS 9, Nov. 2016
SAS Certified Advanced Programmers for SAS9, Nov. 2016

Services

Session Chair & paper reviewer:
- Session Chair & paper reviewer of Annual Meeting of National Council on Measurement in Education (2023), Chicago, IL
- Paper reviewer of Annual Meeting of National Council on Measurement in Education (2024-2025)
- Paper reviewer of Annual Meeting of American Educational Research Association (2024-2025)

Awards

Mar. 2021: Melvin R. Novick Award
- College of Education, The University of Iowa
  - This award was established as a memorial for Professor Melvin R. Novick by the College of Education and Dr. Novick’s wife, Naomi. It is presented annually to a doctoral student who has shown outstanding academic performance and promise of the highest level of achievement inresearch in the field of educational measurement and research.
Mar. 2020 & Mar. 2021: Research Award
- College of Education, The University of Iowa
  - This award is in recognition of an outstanding graduate student who has demonstrated outstanding research achievement through the academic year in educational measurement and statistics program at the University of Iowa.
Feb. 2020: Blommers/Hieronymus/Feldt Fellowship
- College of Education, The University of Iowa
  - This award is in recognition of an outstanding doctoral student who has demonstrated academic achievement, professional promise, and have completed one full year in educational measurement and statistics program at the University of Iowa. This award is made possible by gifts to the University of Iowa Foundation from friends and colleagues of Professors Blommers, Hieronymus, and Feldt.
Oct. 2018: Third Place in 2018 Midwest Big Data Hackathon
- The University of Iowa
  - This award is in recognition of the third-place excellent team project out of 40 competitive team projects in the 2018 Midwest Hackathon competition at the University of Iowa.

Publications

The Movement and Stillness, Reasonable Interest, and Entirely Free Feelings of Landscape Poetry of Su Shi

Xu, Guanlan. (2009). "The Movement and Stillness, Reasonable Interest, and Entirely Free Feelings of Landscape Poetry of Su Shi. " Modern Chinese. 1(1).

A Study on “Zi X” Typed Styles in Pre-Qin and Han Dynasties

Xu, Guanlan. (2010). "A Study on “Zi X” Typed Styles in Pre-Qin and Han Dynasties." Journal of An-Qing Normal College. 1(1).

Expanding G-Theory Models to Incorporate Congeneric Relationships: Illustrations Using the Big Five Inventory

Walter P. Vispoel, Guanlan Xu & Murat Kilinc (2020) Expanding G-Theory Models to Incorporate Congeneric Relationships: Illustrations Using the Big Five Inventory, Journal of Personality Assessment, DOI: 10.1080/00223891.2020.1808474

Using Parallel Splits with Self-Report and Other Measures to Enhance Precision in Generalizability Theory Analyses

Walter P. Vispoel, Guanlan Xu & Wei S. Schneider (2021): Using Parallel Splits with Self-Report and Other Measures to Enhance Precision in Generalizability Theory Analyses, Journal of Personality Assessment, DOI: 10.1080/00223891.2021.1938589

Interrelationships between latent state-trait theory and generalizability theory within a structural equation modeling framework

Vispoel, W. P., Xu, G., & Schneider, W. S. (2021). Interrelationships between latent state-trait theory and generalizability theory within a structural equation modeling framework. Psychological Methods. Advance online publication. https://doi.org/10.1037/met0000290

Integrating Bifactor Models into a Generalizability Theory Based Structural Equation Modeling Framework

Walter P. Vispoel, Hyeryung Lee, Guanlan Xu & Hyeri Hong (2022) Integrating Bifactor Models into a Generalizability Theory Based Structural Equation Modeling Framework, The Journal of Experimental Education, DOI: 10.1080/00220973.2022.2092833

Expanding Bifactor Models of Psychological Traits to Account for Multiple Sources of Measurement Error

Vispoel, W. P., Lee, H., Xu, G., & Hong, H. (2022). Expanding bifactor models of psychological traits to account for multiple sources of measurement error. Psychological Assessment.

Book Chapter: Item Response Theory

Chapter Ackerman, A., Ma, Y., Ma, M., Pacico, J. C., Wang, Y., Xu, G., Ye, T.,Zhang, J., Zheng, M. (2022). Item Response Theory. In Editor R. J. Tierney, F. Rizvi, K. Ercikan. (Ed.) International Encyclopedia of Education (Fourth Edition, 72-85). Elsevier. https://doi.org/10.1016/B978-0-12-818630-5.10010-7