Average scores are difficult because they do not diminish the counterfactual that cyber charter schools may recruit the students who typically perform at a lower level. However, the scores do tell us (at the very minimum) that these schools at least may not be raising the achievement levels of these students. I see studies like this often!
I do believe their conclusion matches their data:
“Consistently poor performance on state assessments by cyber charters is sobering, especially in light of the fact that cyber enrollment continues to grow, with a marked increase in special education students. It is also troubling that comprehensive and consistent data are not available on PDE’s website to fully examine the sector’s performance. However, the initial analyses included in this document should be reviewed carefully as state policymakers decide whether to expand this sector.”