It appears that Washington, DC's new teacher evaluation system, IMPACT, is what it is cracked up to be.

Looking at the second-year stats, IMPACT resulted in the top 663 teachers (16 percent of the workforce) being eligible for bonuses of up to $25,000. That's about the same number as last year, and, as we wrote about before, approximates pretty closely to what economists estimate is the percentage of truly exemplary teachers on the average district payroll.

About a third of these teachers earned this distinction for the second year in a row and are now eligible for a permanent base pay increase of up to $20,000.

Both the bonus and base pay increase are contingent upon teachers agreeing to give up tenure protections. Last year, approximately 40 percent of eligible teachers rejected the bonus. There's no word yet on teachers' decisions this year.

On the flip side, 206 teachers are being dismissed for poor performance (5 percent of the workforce), up from 135 last year. Of the 206 teachers let go this year, 65 were rated as "ineffective," while another 141 were rated "minimally effective" for the second consecutive year. Just over half of those teachers rated "minimally effective" a year ago were rated "effective" this year, and 3 percent were rated "highly effective."

This year principals were allowed to make exceptions to dismissing teachers who received a "minimally effective" rating two years in a row. The announcement of such a waiver had a lot of folks snickering that new Chancellor Kaya Henderson didn't have Michelle Rhee's guts, but only four teachers were saved with the change. In other words, principals largely agreed that the teachers IMPACT said should be let go really needed to go.