Evaluation of effects of mass media-based health interventions requires accurate assessments of exposure, which can be difficult to obtain when young children are the primary audience. Alam Simsim, the Egyptian version of Sesame Street, aired nationally in Egypt to teach preschoolers about numeracy, literacy, and gender-equitable attitudes. The purpose of this article was to assess the effect of the program through a first-of-its-kind household-level survey that interviewed caretakers (n = 426) and preschoolers (n = 486). The authors introduced and tested the efficacy of a parsimonious measure of exposure: children's recognition of the primary characters of the program. Overall, the authors' models explained as much as 53% of the variance in children's learning; exposure to the program was significantly associated with learning. Furthermore, the parsimonious measure of exposure was as effective as a more elaborate child-reported measure. Relative to these two measures of exposure, caretakers' report of children's viewing was not as good a predictor of learning.