A list with class "aTest" containing the following
components: test statistics stat, critical value
critical.value and the result of the test
result, i.e. whether the additivity hypothesis has
been rejected.
Details
The critical value can be computed in advance and given
in the parameter critical value. If not a function
critical.values is called to do that.
References
Tukey, J.W.: One Degree of Freedom for Non-additivity,
Biometrics5, pp. 232--242, 1949.