One Laptop Per Child is not improving reading or math. But, are we learning enough from these evaluations?

A few months ago, the first randomized evaluation of the One Laptop Per Child (OLPC) came out as a working paper (you can find a brief summary by the authors here), after circulating in the seminar/conference circuit for a while. Many articles and blogs followed (see a good one here by Michael Trucano and find the short piece in the Economist and the responses it generated from OLPC in the comments section) because the study found no effects of OLPC in Peru on test scores in reading and math, no improvements in enrollment or attendance, no change in time spent on homework or motivation, but some improvements in cognitive ability as measured by Raven’s Progressive Colored Matrices.