Here you must control for the fact that the existence of a charter school may reflect factors in an area that also determine the area's demand for certain teacher characteristics. (educationnext.org)
But he was two years behind me in school and might have been held back even more except for the kindness of certain teachers. (bookbrowse.com)
And, what he found is that there were certain teachers who were reliably better able than others to improve their student's performance on these proxy measures. (greatergood.berkeley.edu)