In Reply.—We are pleased that Obel et al have tried to replicate our findings in a Danish data set of convenience and happy to reply to their letter. They are surprised that the association between television-viewing and attentional problems that we found was similar at ages 1 and 3. We are not. Many of the children in our study were included in both the age-3 and the age-1 analysis, and in fact the amount of television viewed at age 3 years is highly correlated with the amount viewed earlier.1 Thus, it is not surprising that television viewed at 3 years and at 1 year had similar odds ratios within the context of our data set. Their next point is that they found an association between television-viewing and behavioral problems in their data set at age 31/2 years but not in subsequent years. In reviewing their data, it must first be noted (as they too acknowledge) that Danish children watch considerably less television than US children do. Fewer than 6% of children in their sample watched >2 hours per day at age 3 years as opposed to >50% of US children at the same age.2,3 Their analysis therefore has considerably less power than ours did to detect a significant difference at these levels of viewing. In addition, as underpowered as they are, they do report an odds ratio of 2.0 for “probable and likely” ADHD cases at 11 to 12 years. Although this finding is not significant as the 95% confidence interval extends from 0.7 to 5.5, with more data in this range it might have been. Moreover, it is also possible that the kinds of programming available in the United States and Denmark are different. Different types of children's programming have been shown to vary with respect to the pacing and to lead to differences in children's attention spans at young ages.4–8Finally, we concur that better research of the effects of television-viewing in this age group is needed. It has been said that “many parents are enlisting the help of a stranger to raise their children.”9 That stranger's influence warrants more robust study. We are pleased to be part of that effort.