In Enrollment and Achievement in Ohio’s Virtual Charter Schools, the Fordham Institute takes a robust, nuanced look at Ohio’s substantial number of e-schools (more commonly known as full-time virtual charter schools). The report paints a troubling picture of these schools’ performance and offers valuable policy recommendations for driving K–12 online learning toward a better future. But readers should note that it also suffers from four significant limitations that are shared by most other studies of virtual charters. This is not the analysts’ fault; it’s intrinsic to the data that are currently available to measure the outcomes of e-school students.