Today, obtaining an entry job into teaching is virtually tantamount to an indefinite contract that stays in force regardless of actual effectiveness in the classroom. (educationnext.org)
Value - added estimates for a teacher can fluctuate for a variety of reasons, many not necessarily related to actual effectiveness at producing student gains on achievement tests. (blog.k-12leadership.org)
This can occur, regardless of what is actually happening in terms of actual effectiveness across America's classrooms, when the purported value that teachers add to or detract from student learning (i.e., 50 % of the state's model) is to substantively count, because VAM output is not calculated in absolute terms, but rather in relative or normative terms. (vamboozled.com)