It is shown that the L-method is basic to test-building and to all combining of scores where the several sub-parts of a composite are weighted according to their respective standard deviations, i.e., with “equal gross score weights” or by “adding the several sub-scores.” With chiefly a listing adding machine, a few celluloid strips, and a master matrix table of L's, one may, in a fraction of the time and with equally good or even better practical results, easily duplicate, with test-building material most of the feats obtainable by multiple regression equations.