KENTWOOD, MI -- Eight-year-old Cora Hovermale fires up a computer at Kentwood's Meadowlawn Elementary and meets her chosen avatar - a casually dressed girl - ready to help tackle that day's lesson.

Students in kindergarten through eighth grade who have been taught and tested against Common Core State Standards, through an online adaptive benchmark and instruction system called iReady, are ...

Corrected: An earlier version of this story noted an incorrect cost estimate for using daily tutoring to catch students up on lost instruction. The iReady study estimated it would cost $66 billion.