The privateers have no good definition or reliable way of measuring a teacher's effectiveness, so they leave it undefined. Sometime it means value-added test scores -- even though it is clear from research that this is a very incomplete, unreliable, unfair and often counterproductive way to measure effectiveness.
Sometimes it means leaving it up to the principal to make arbitrary decisions based on who he or she likes.
In Michelle Rhee's case, she fired 266 veteran teachers, and later claimed many of them had been accused of sex abuse .....a claim which turned out to be entirely false.
Rhee has launched a new teacher evaluation system that is based half on value-added standardized test scores (at least for teachers in grades 4-8) and half on classroom observations, calculated in a complex system that is a composite of 20 different evaluation systems.
For teachers in untested grades, more than 80% is based on this system, called IMPACT. Among the characteristics that classroom observers are supposed to rate is the teacher’s ability to “instill student belief in success” through chanting etc.
"Observers are expected to check every five minutes for the fraction of students paying attention. Teachers are supposed to show that they can tailor instruction to at least three "learning styles" (auditory, visual or tactile, for example). They can lower their scores by "using sarcasm that visibly hurts or decreases the comfort of one or more students." Among the ways instructors can demonstrate that they are instilling student belief in success is through "affirmation chants, poems and cheers."
I guess the last of these is an attempt to emulate KIPP and other charter schools, many of whom have elaborate chanting systems.