The conventional proportional odds (PO) model assumes that data are collected using simple random sampling by which each sampling unit has the equal probability of being selected from a population. However, when complex survey sampling designs are used, such as stratified sampling, clustered sampling or unequal selection probabilities, it is inappropriate to conduct ordinal logistic regression analyses without taking sampling design into account. Failing to do so may lead to biased estimates of parameters and incorrect corresponding variances. This study illustrates the use of PO models with complex survey data to predict mathematics proficiency levels using Stata and compare the results of PO models accommodating and not accommodating survey sampling features.
Liu, Xing and Koirala, Hari
"Fitting Proportional Odds Models to Educational Data with Complex Sampling Designs in Ordinal Logistic Regression,"
Journal of Modern Applied Statistical Methods:
1, Article 26.
Available at: http://digitalcommons.wayne.edu/jmasm/vol12/iss1/26