Difference Between ANCOVA and ANOVA


ANCOVA and ANOVA are two techniques used in statistical analysis. If you are confused between ANCOVA and ANOVA, and wondering what the difference between ANCOVA and ANOVA is, you are not alone as there are many who think along these lines. For starters, both are statistical techniques for equating groups or samples on one or more variables. There are slight differences in methodology while serving the same purpose. Let us see what these tow terms stand for.


ANCOVA stands for Analysis of Covariance. It is a method of analysis having two or more variables with at least one continuous and also one categorical predictor variable. ANCOVA merges ANOVA and another method called regression in case of continuous variables. It is basically a method to test the effect or otherwise of certain factors on outcome variable when variance has been removed. Making use of covariant, ANCOVA improves statistical power. ANCOVA is a liner regression model of analysis which implies that the relationship of variables (dependent and independent) has to be linear.


ANOVA stands for Analysis of Variance in statistics. The purpose of ANOVA is to check whether data from various groups have a common mean or not. This method of analysis gives better results than a t-test of two samples. Conducting 2-3 t-tests has a probability of coming up with error, and thus ANOVA is more efficient if you need to compare means of several groups.

Difference between ANCOVA and ANOVA

Talking of differences, for someone who is not well versed with both methods would be hard pressed to find a difference. Both ANCOVA and ANOVA are available in different designs for the purpose of analysis. Let use see .

Major differences between ANCOVA and ANOVA

• While ANCOVA makes use of covariate, ANOVA does not depend, and in fact purposely avoids covariate.

• BG variation is a special feature of ANOVA whereas ANCOVA divides BG variation into TX and COV.

• Both ANOVA and ANCOVA make use of WG variation but ANCOVA divides it for individual differences as COV while ANOVA uses it only for individual differences.

• While both are good methods of analysis, ANCOVA is supposed to have more power and unbiased among the two.