A meta-analysis of 21 instructional treatments aimed at enhancing the skill
of deliberately deriving word meaning from context during reading shows a
medium effect size of 0.43 standard deviation units (p < .000). An explorat
ory multilevel regression analysis shows that clue instruction appears to b
e more effective than other instruction types or just practice (beta = 0.40
). Effect size correlates negatively with class size (beta = -.03). Implica
tions for instruction and future research are discussed. Future studies sho
uld investigate the effect of instruction on both the skill of deriving wor
d meaning from context and incidental word learning to evaluate its contrib
ution to vocabulary growth.