When a binary or ordinal regression model incorrectly assumes that error variances are the same for all cases, the standard errors are wrong and (unlike OLS regression) the parameter estimates are biased. Heterogeneous choice (also known as location-scale or heteroskedastic ordered) models explicitly specify the determinants of heteroskedasticity in an attempt to correct for it. Such models are...

Modelling repeated ordinal score data is a common statistical problem, across many application areas. The proportional-odds model is widely applied to such repeated ordinal scores and can be fitted in the repolr package (repeated measures proportional odds logistic regression) in R using the method of generalized estimating equations (GEE). The GEE approach specifies a model for the mean of the...

For categorical data, the relationship between visual displays of the data and models is not very well explored, even though for categorical data and loglinear models strong relationships do exist. Starting from assessing odds ratios visually, interaction effects of variables can be examined using mosaic plots. Cumulative link models provide a way to describe trends between ordinal variables. I...

This introduction to the R package multgee is a slightly modified version of ?, published in the Journal of Statistical Software. To cite multgee in publications, please use ?. To cite the GEE methodology implemeted in multgee, please use ?. The R package multgee implements the local odds ratios generalized estimating equations (GEE) approach proposed by ?, a GEE approach for correlated multino...

Rank oriented models do not assume that we can exactly quantify the value of an alternative. They do not even assume that we know anything about the distribution of the utility, loss or other observable quantities characterizing an alternative’s utility. We only assume that we are able to rank the alternatives drawn. However the necessity to introduce search cost in our considerations seem to d...

Coronavirus disease 2019 (COVID-19) is a new type of virus that has been found to have infected human since it first appeared in Wuhan, China, December 2019. This study aims determine the factors influence risk zone status COVID-19 spread Indonesia using ordinal logistic regression. The regression model this uses proportional odds because researcher assumes probability predictor variable coeffi...