Online schooling: Who is harmed and who is helped?

[Commentary] Online courses have the potential to improve instruction at every level of education. Adaptive online courses can allow students to learn at their own pace, with material adjusting to fit the needs of both advanced and remedial learners. Online courses can also open up more curricular offerings in schools that lack specialists, such as those in rural areas. Online courses are particularly attractive to school and district leaders looking for ways to trim costs. Teacher salaries are the key driver of instructional costs at every level of education, so any technology that allows a teacher to instruct more students can free up funds that can be used for other purposes.  Whether cost savings are realized depends on production costs, which can be high for universities that are rolling out their own digital content. Are online courses fulfilling their promise?