# ANCOVA: How does a covariate give insight when comparing the mean to the adjusted mean?

When comparing the direction and magnitude of the difference between the original means and the adjusted means what does the change say about the covariate?

For example: IV = Grade, DV = Test Score, Covariate = IQ Score

Am I correct in assuming that if a group's adjusted mean is higher than its original mean that the effect of the covariate (higher IQ) is that it decreases the DV (Test Score) thus resulting in the higher adjusted mean?

Thanks.

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 Welcome to the site.I attempted to clarify your first paragraph. If I messed up, please correct it. As to your question, why not just look at the parameter estimate for the covariate? That seems much more straightforward – Peter Flom Nov 13 '12 at 3:58 I see the parameter estimate read out in SPSS but am unclear how to interpret it. – Arctic Nov 13 '12 at 4:12 The parameter readout for the covariate is the predicted relationship between a 1 point gain on IQ (the covariate) on score (the DV). At least, unless you have coded something strangely. – Peter Flom Nov 13 '12 at 10:48 I seem to have figured it out, the direction and magnitude of the adjustment on the DV mirrors the adjustment of the covariate, is this correct reasoning? – Arctic Nov 13 '12 at 18:16 I think so, but you are using odd language. – Peter Flom Nov 13 '12 at 22:51