Masson and McDaniel (1981) showed that an additional testing
session after study resulted in higher performance on delayed recall and
recognition tests and, more important, that the additional test yielded
higher organization on the final recall test. Their primary measure of organization was the adjusted ratio of clustering (ARC), which is a
measure of how often words from the same category are recalled together
in free recall with an adjustment for the overall level of recall. Scores range
from #1 to 1, with 1 representing perfect organization or clustering and
0 representing chance clustering (Roenker, Thompson, & Brown, 1971).
Masson and McDaniel’s results suggested that the test resulted in
improved organization and higher recall on final tests