Hello! I am a Research Assistant in Educational Measurement and Evaluation at Trakya University, Faculty of Education, and a PhD candidate in the same field at Hacettepe University.

My work mostly includes Monte Carlo simulations to examine factor retention methods' performance with ordinal datasets in psychoeducational contexts (i.e., cross-loadings, hierarchical structures, and missing data) and what these findings imply for researchers and practitioners who need to determine the appropriate number of factors. I also work with large-scale assessment data (PISA, PIRLS, TIMSS, ICILS) on measurement invariance and item-format effects.

This site collects my publications, talks, and the software and teaching materials I share.

Tugay Kaçak


Research at a glance

Factor retention

How many factors are there, really? Parallel analysis, EGA, Hull, CD and friends — stress-tested with ordinal, mixed-format and hierarchical data.

Reliability

What missing data handling and correlated errors do to alpha, omega and their relatives.

Large-scale assessment

Measurement invariance and item-format effects across countries in PISA, PIRLS, TIMSS and ICILS.


News


Thanks for stopping by. Corrections and collaboration ideas are always welcome.