'Sizable' number of poorly performing D.C. teachers face ax

D.C. Schools Chancellor Michelle Rhee will fire a large number of teachers and school staff by next week based on ineffective performance, said a top aide — a move certain to become a factor in the tight mayoral race.

“It’s going to be a sizable number,” Deputy Chancellor Kaya Henderson said at a briefing Thursday about details of D.C. Public Schools’ evaluation tool. The tool, called Impact, was used for the first time in 2009-2010 to determine employees’ effectiveness, based mostly on five observations as well as measures of students’ academic progress. Teachers evaluated as “highly effective” will be eligible for performance bonuses in 2010-11.