Robust tests for comparing the dispersions of several
Fisher or Watson distributions on the sphere
Summary. The usual test for comparing the dispersions of two or more
samples of unit vectors from Fisher distributions is not reliable when there
are small departures from the Fisherian model. This paper describes another
method which is less sensitive to such departures, and gives examples of its
use. Similar methods are described for comparing two or more samples of
axes from Watson bipolar or girdle distributions.
Key words: concentration parameter, Levene test, spherical data