This work is valuable, but I personally would like to put more focus on improving teaching and learning - helping teachers do better, helping students do better, creating better learning environments and curricula.

For example the budget of this study came out to about $15000 per teacher. What if instead we spent $5000 of that for professional development / training for the teacher, $5000 for a classroom set of chromebooks, and gave the teacher a $5000 raise. That alone would cause some significant improvements, I believe (not that that is ALL that is needed, and there are so many bigger issues that need to be tackled as someone else mentioned, such as poverty and inequity).

But when we talk about "good" teaching and "bad" teaching, we are treating it like it is a simple craft that is mastered or not mastered. Teaching is like engineering, it involves design, and design is about making things better (see this prezi on learning design: http://prezi.com/b44jwdgvs8nl/olds-mooc-introduction/ )