GENERAL- AND  GROUP-FACTOR METHODS      319
' simple ' structure can hardly be accepted as a guarantee
of their concrete psychological significance. Rather, I
should argue, if the initial data have led to problems that
a straightforward factorial technique is incompetent to
solve, that means that the experimental stage of the re-
search was inappropriately planned.
Finally, once we start calculating coefficients to allow for
possible overlap, where are we to stop ? Unless our tests
fall into abruptly separated groups, the group-factors will
quickly spread out into general factors, each extending over
every test : and in that case, even when dealing with
residual correlations, the analysis will still have to be applied
to the entire table at each step, and thus the procedure
adopted will remain a ^c general-factor method ' throughout.
And so we come to an examination of what I have called
^c general-factor methods/