Questions tagged [polr]

polr refers to a R function in package MASS for ordered logistic or probit regression.

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Plot predict probabilities wiht ggplot2 and brms [closed]

I'm a PhD student in psycholinguistics and I'm having trouble in modeling some ordinal data. I have an ordinal response (completely disagree, disagree, neutral, agree, completely agree) and two ...
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106 views

Can someone explain what the Brant test in R does?

I’m using R to run proportional odds models through the polr function in the MASS package. I want to see if the proportional ...
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117 views

Ordinal logistic regression interpretation of polr summary in r

I am trying to interpret the coefficients for the polr model. Where each predictor has three levels, Dissatisfied, Neutral, and Satisfied. Dissatisfied is the baseline. The dependent variable has the ...
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1answer
51 views

Ordinal logistic regression (polr in R): DV wrong level order

I am (trying) to conduct an ordinal logistic regression for the first time using the polr function in r. I seem to be encountering a problem with the order of my levels of my DV. My DV should have ...
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17 views

What to do if an ordinal logistic regression with continuous predictors has a cell in the expected frequency table that is <1

Thank you in advance for your help. I am running an ordinal logistic regression with a DV of 5 levels and two continuous predictor variables. So, for goodness of fit, I need to run Lipsitz or the ...
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21 views

What is a good algorithm for measuring the relationship between numerical input variables and ordered categorial output?

I have a dataset with 50 numerical input variables and 1 output column. The output is categorical and ordered. I want to describe the relationship between the numerical variables and the categorial ...
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182 views

Random effects for ordinal logistic regression?

I am relatively new to R. I am currently using R studio to run an ordinal logistic regression for some research. Initially I just ran the ordinal logistic regression using R's polr function, I didn't ...
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52 views

Interpreting interaction odds ratios in ordinal regression

I have run an ordinal regression in R using polr from the MASS package. I'm trying to interpret an interaction. Both predictors are categorical. Here is an example: Predicting success in the job ...
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107 views

ordered logistic regression marginal probabilities hit ceiling

I'm running an ordered logistic regression with 3 classes, and I am able to predict the probability of each observation belonging to each class. For some reason one class' probabilities (top40) never ...
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0answers
105 views

Ordered probit model prediction: why highest probabilities and not number of thresholds exceeded?

I'm running ordered probit regression models with polr in R. This question states that for prediction, ...
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1answer
580 views

Ordinal Logistic Regression with Polr: Compare multiple treatments

Let's say I have information about three stages of cancer (Stage 1, Stage 2, Stage 3) and three treatment groups. Now I'd like to compare if the odds ratio for all of these three groups are different. ...
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1answer
473 views

Interpreting results of multinomial model using polr

I am trying to correctly interpret and plot the effects of a multinomial model fit in R. The data and script are here for reproducing the problem. The multinomial variable describes different ...
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22k views

How to use ordinal logistic regression with random effects?

In my study I will be measuring workload with several metrics. With heart-rate variability (HRV), electrodermal activity (EDA) and with a subjective scale (IWS). After normalization the IWS has three ...
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300 views

Ordered Logistic Regression GWAS

I am attempting to do an ordered logistic regression in R on SNP matrixes (presence absence matrix 1 or 0) with three outcomes (1,2,3). I am having an issue of 0 p-values when low numbers (<5%) ...
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332 views

How should I determine degrees of freedom for t-test in ordinal regression?

I consider a proportional odds (ordinal regression) model, as described in Agresti (2002) and estimated by R base package ...
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2answers
7k views

Checking the proportional odds assumption holds in an ordinal logistic regression using polr function

I have used the ‘polr’ function in the MASS package to run an ordinal logistic regression for an ordinal categorical response variable with 15 continuous explanatory variables. I have used the code (...
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383 views

difficulties evaluating if a ordinal multnomial model fitted with polr (in Rstudio) can be used for predicting over new data

I'm getting very different output when i perform a multinomial ordinal model depending on wether I scale or not my data first. Anyone could tell me why? Here are the results with raw data: ...
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1answer
302 views

Is there an R package to check the proportional odds assumpion? [closed]

is there an R package/function to implement the parallel slope test given a clm (ordinal package) or polr (MASS) package?
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173 views

Understanding ordered logistic regression

I have the following toy data: ...