Dear all. I am struggling to interpret the residual plots from the Dharma package. If we find a red line in residual plot,does it mean there is heteroscedasticity in the model for the predictor variables? If the solid line matches with the dashed line, can we say there is no heteroscedasticity? I have attached three residual plots here to understand heteroscedasticity of the model. In the first plot, quantile deviationare detected by the red line, so there is heteroscedasticity in the model. This is for the model which includes all covariates. Then I created the residual plot for one by one covariate to know which predictors are responsible for variable dispersion. The 2nd and 3rd plots are for just one predictor. In the 2nd plot, three solid lines are red and there exhibits a clear deviation from the dashed line. So, there is heteroscedasticity in the model for that predictor. The 3rd plot is box plot.The distribution for each factor level should be uniformly distributed, so the box should go from 0.25 to 0.75, with the median line at 0.5 (within-group ). As the two box plots are red and it shows deviation of median line from 0.5, so there is heteroscedasticity in the model for the predictor. The 4th plot shows less deviation. Can we say this is better? I need your expert suggestions and also please refer me to any article where I find a clear explanation of heteroscedasticity checking by residual plot using DHARMA.Many thanks. Kindest regards, Tahsin -------------- next part -------------- A non-text attachment was scrubbed... Name: Rplot1.png Type: image/png Size: 98722 bytes Desc: not available URL: <https://stat.ethz.ch/pipermail/r-sig-mixed-models/attachments/20210602/4687a53d/attachment-0004.png> -------------- next part -------------- A non-text attachment was scrubbed... Name: Rplot 2.png Type: image/png Size: 142547 bytes Desc: not available URL: <https://stat.ethz.ch/pipermail/r-sig-mixed-models/attachments/20210602/4687a53d/attachment-0005.png> -------------- next part -------------- A non-text attachment was scrubbed... Name: Rplot 3.png Type: image/png Size: 45874 bytes Desc: not available URL: <https://stat.ethz.ch/pipermail/r-sig-mixed-models/attachments/20210602/4687a53d/attachment-0006.png> -------------- next part -------------- A non-text attachment was scrubbed... Name: Rplot 4.png Type: image/png Size: 85031 bytes Desc: not available URL: <https://stat.ethz.ch/pipermail/r-sig-mixed-models/attachments/20210602/4687a53d/attachment-0007.png>
Interpretation of residual plot using DHARMA package for mixed model
1 message · Tahsin Ferdous