Reasons and advantages of using an ANCOVA instead of a Regression

#1
Hello everyone,

Just wondering if any of you could help me. Just wondering when the variables I’m using can be used for both ANCOVA and regression, what would be the advantages of using an ANCOVA?

The way I’m using it is that the impact of the variable of interest is being examined by including it as a covariate.

Have been told its the correct test, but I’m just trying to get clear reasons in plain English so i can understand what its advantages are, as opposed to the regression.

Tnks for the help.
 

Dragan

Super Moderator
#2
Briefly, ANCOVA is a combination of ANOVA and Regression. Thus, with ANCOVA, you are looking for differences between the adjusted means of groups i.e., adjusted by the inclusion of the covariate. You would also obtain a reduction in error if the correlation between the dependent variable (or variate) and the covariate is significant. The other purpose of ANCOVA is adjust the means of the covarate (in each group) so that they are equal, which occurs when there are differences between the means of the covariate that can occur from random sampling to treatment conditions.