Wei He, PhD
Principal Psychometrician
Wei He provides psychometric expertise and support to NWEA assessment products and is currently leading psychometric efforts for state assessment in Alaska . She is passionate about leveraging psychometric theory, statistical methods, and data analytics to develop innovative and efficient assessments that can better capture student learning and address practical challenges in the assessment field. Dr. He’s research covers a range of topics focused on the unique challenges posed by computer-adaptive and multistage testing, including adaptive algorithm design, item pool design for adaptive tests, scale stability monitoring in a continuous testing environment, test assembly, and item field-testing and calibration.
Dr. He has published in peer-reviewed journals such as Educational and Psychological Measurement and Journal of Educational Measurement on topics including item selection and item pool design in adaptive testing, missing data treatment, differential item functioning, and item response theory model estimation methods. She has also served as a reviewer for peer-reviewed journals and conferences and frequently presents at industry conferences. Dr. He holds a PhD in measurement and research methodology from Michigan State University.
Publications by Wei He
Achievement and Growth Norms for Course-Specific MAP Growth Tests
This report documents the procedure used to produce the achievement and growth user norms for a series of the course-specific MAP® Growth™ subject tests, including Algebra 1, Geometry, Algebra 2, Integrated Math I, Integrated Math II, Integrated Math III, and Biology/Life Science. Among these tests, Integrated Math I, Integrated Math II, Integrated Math III, and Biology/Life Science were the first time to have their norms available. The remaining tests, i.e., Algebra 1, Geometry, and Algebra 2, had their norms updated including receiving more between-term growth norms by using more recent test events. Procedure for norm sample selection and a model-based approach using the multivariate true score model (Thum & He, 2019) that factors out known imprecision of scores to generate the norms are also provided in detail, along with the snapshots of the achievement and growth norms for each test.
Products: MAP Growth
Topics: Measurement & scaling
Achievement and growth norms for English MAP Reading Fluency Foundational Skills
This report documents the norming study procedure used to produce the achievement and growth user norms for English MAP Reading Fluency Foundational Skills.
Products: MAP Reading Fluency
Topics: Measurement & scaling
MAP Growth item parameter drift study
This report documents the results of an item parameter drift study designed to check the parameter stability of MAP Growth items.
Products: MAP Growth
Topics: Computer adaptive testing
An investigation of item parameter invariance using focused calibration samples for MAP Growth
Two studies were conducted to evaluate whether the existing MAP Growth item parameter estimates are invariant across different calibration samples.
Products: MAP Growth
Topics: Computer adaptive testing
A comparison of item parameter estimates in Pychometrik and the existing item calibration tool
This study evaluates the performance of Pychometrik, a new item calibration tool, against the existing tool for MAP Growth.
Topics: Item response theory
The report documents the process NWEA followed to determine and validate the cut scores for fall, winter, and spring that can be used to identify students in Grades K–8 who have severe learning difficulties and need intensive intervention in reading and mathematics.
Products: MAP Growth
Topics: Guidance
MAP Growth K-2 item fit analysis study: A follow-up study
This is a follow-up analysis to the May 2019 item fit analysis study to evaluate the fit of the items whose item difficulties were adjusted in the more recent 2020 follow-up scale alignment study.
Products: MAP Growth
Topics: Item response theory
