At 10:23 PM +0200 7/23/08, Tobias Verbeke wrote:>Angelo Scozzarella wrote:
>
>>what the command for the point-biserial correlation?
>
>Have a look at the polycor package by John Fox.
>
>http://cran.r-project.org/web/packages/polycor/index.html
>
>HTH,
>Tobias
A point-biserial correlation is just a Pearson correlation where one
of the variables is dichotomous. Thus, the command is just the
normal cor function.
The polycor package will give (among other things) the biserial
correlation (a correlation between a dichotomous variable and a
continuous variable with the assumption that the dichotomous reflects
a normal that was artificially dichotomized).
Bill
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