The Duke paper reports that the negative effect on test scores was not universal, but was largely confined to lower-income households, in which, the authors hypothesized, parental supervision might be spottier, giving students greater opportunity to use the computer for entertainment unrelated to homework and reducing the amount of time spent studying.
The North Carolina study suggests the disconcerting possibility that home computers and Internet access have such a negative effect only on some groups and end up widening achievement gaps between socioeconomic groups. The expansion of broadband service was associated with a pronounced drop in test scores for black students in both reading and math, but no effect on the math scores and little on the reading scores of other students.