Hi everyone.
This is my first time on this forum … thank you for accepting me!
I have run a Quade's rank analysis of covariance (Quade, 1967) using SPSS.
The reason I did not use a straight ANCOVA was because three of the five assumptions underpinning parametric ANCOVA were not confirmed in my data. As the non-parametric method (Quade's) identifies, you are running the ANOVA part of the ANCOVA analysis on the rank-ordered dependent variable with the residuals saved in the OLS regression part of the ANCOVA analysis as the factor. The residuals are clearly the differences between the rank-ordered DV scores minus the predicted scores from the OLS regression model.
All I am able to do currently is, based on the F-ratio (Quade's index), is accept or reject the null.
Any post-hoc follow up is based on rank ordered data. I need to be able to refer the data back to the original units of measurement as a post-hoc procedure otherwise the results will make no sense!
Does anybody have some advice about how I might resolve this?
This is my first time on this forum … thank you for accepting me!
I have run a Quade's rank analysis of covariance (Quade, 1967) using SPSS.
The reason I did not use a straight ANCOVA was because three of the five assumptions underpinning parametric ANCOVA were not confirmed in my data. As the non-parametric method (Quade's) identifies, you are running the ANOVA part of the ANCOVA analysis on the rank-ordered dependent variable with the residuals saved in the OLS regression part of the ANCOVA analysis as the factor. The residuals are clearly the differences between the rank-ordered DV scores minus the predicted scores from the OLS regression model.
All I am able to do currently is, based on the F-ratio (Quade's index), is accept or reject the null.
Any post-hoc follow up is based on rank ordered data. I need to be able to refer the data back to the original units of measurement as a post-hoc procedure otherwise the results will make no sense!
Does anybody have some advice about how I might resolve this?