ANCOVA

[Jeff]

Greetings all,

I have a question about ANCOVA which I've wondered about for some
time. I've seen several sources (textbooks) which explicitly state
that covariates used in this analysis must be of continuous scale.
However, I've also seen a number of studies which have used gender as
a covariate. My understanding is that ANCOVA uses linear regression
to identify the variance associated with the covariate, and since
regression allows the use of dichotomous independent variables, is it
acceptable to use a dichotomous variable as a covariate in ANCOVA?

Whatever input you have would be appreciated.

Kind regards,

Jeff