This study tested the general monitoring skill hypothesis, which state
s that skilled adult learners monitor their comprehension using domain
-general metacognitive knowledge in addition to domain-specific knowle
dge. College students completed 8 tests of fluid and crystallized abil
ity. The 8 tests yielded 3 performance components, whereas measures of
monitoring yielded 2 principal components. These findings supported 2
main conclusions: Monitoring scores are correlated across multiple do
mains, and individuals may possess separate general monitoring skills
for fluid and crystallized tasks. The authors also examined the degree
to which modular, information-encapsulation, and domain-general theor
ies of cognition accommodated these findings. Domain-general theories,
such as the general monitoring skill hypothesis, provided the best ex
planation of the data.