# [Statistica] help!

#### SimonGeo

##### New Member
Hi,

Is it possible to display significance levels (Kendall Tau) in the output matrix? At the moment it is only the Correlation Coefficient, the number of observations would be handy to...

Thanks :tup:

#### JenB

##### New Member
Well, there is not an option for this, however, the computation of the p-value is based upon a normal approximation and is easy to compute by hand.

The computation could be done as follows:
Z = T / sqrt(Var),
where T = Kendall Tau correlation and
Var = 2*(2*N+5)/(9*N*(N-1)), and
N = Number of observations,

the two tailed approximate p-value is then 2 * NormalCDF(-|Z|).

The formula in STATISTICA for NormalCDF(x) is INormal(x,mean,sd). Here use INormal(-Abs(z), 0, 1).