BOSTON MA.11/ 09 / 2012:Eight grade students returning from lunch walking up stairway with Teacher Christine Adamson ( cq) at UP Academy which was converted from the old Gavin Middle School into a charter school, Unlocking Potential has faced mounting criticism that it has been forcing out students who are flunking their classes or who are overly disruptive, as part of a plan to boost test scores. But data compiled by the School Department shows that students withdrew from Unlocking Potential's UP Academy at a rate lower than the average for middle schools in Boston. ( David L Ryan/Globe Staff Photo ) SECTION: METRO TOPIC 10upacademy