Hortensius, L.M. (2010) The DAOA region is an effect modifier in predicting positive, negative and disorganized schizotypal symptoms in healthy participants. Master's thesis in Psychology, Utrecht University. (Thesis)
Hortensius, L.M. & Wang, C. (2014, April). Practical Guidelines for the Estimation of Multidimensional Ordered Polytomous Models. Paper presented at the annual meeting of the National Council on Measurement in Education, Philadelphia, USA. (Slides / Paper)
Hortensius, L.M. & Weiss, D.J. (2012, August). Small item bank CAT; Interaction of scoring method, termination criteria, and item bank shape. Paper presented at the annual meeting of the International Association for Computerized Adaptive Testing, Sydney, Australia. (Slides)
Hortensius, L.M. & Weiss, D.J. (2012, July). Computerized adaptive testing (CAT) design; Interaction of item bank, scoring method, and termination criteria. Poster presented at the 8th meeting of the International Test Commission, Amsterdam, The Netherlands. (Poster)
Simeone, C.A., Colitz, C.M.H., Colegrove, K.M., Field, C.L., Rios, C., Chandler, H.L., & Johnson, S.P. (2016). Subconjunctival antimicrobial poloxamer gel for treatment of corneal ulceration in stranded California sea lions (Zalophus californianus). Veterinary Ophthalmology, 1-9. (I provided free statistical analysis assistance, a minor contribution to the paper).
These are presentations and notes I wrote for classes or for teaching while at the University of Minnesota. I post these in the hope that they might help others understand the material. The presentations were made for classes and are not exhaustive or guaranteed to be correct. Sources are cited where possible but especially early presentations might lack sufficient citations.
Multidimensional calculus relevant to psychometrics (Presentation)
Statistical error and the impact of measurement error on statistical procedures (Presentation)
EM algorithm in the context of IRT item parameter estimation (Presentation)
Metropolis Hastings Markov Chain Monte Carlo (Presentation)
Putting a confidence interval around 'observed score' versus 'true score' in classical test theory (Notes)
Measurement Invariance in SEM (Class Paper)
Differential Item Functioning tests with R (Class Paper)
The Dirichlet distribution (Notes)