In some experiments where we use ANOVA some of the unexplained variability (i.e. the error) is due to some additional variable (called a **covariate**) which is not part of the experiment. If we can somehow remove the effect of this variable, we could reduce the error variance thus enabling us to get a more accurate picture of the true effect of the independent variable. This is the main goal of **Analysis of Covariance** (**ANCOVA**).

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Sir, is it possible to incorporate Cochran’s Q test and time series analysis to enrich your already rich website. Thank you in advance.

Good idea. I will include Cochran’s Q test in the next release. Time series analysis will have to come a bit later.

Charles