In general, value-added models use statistical formulas to generate estimates of how much a particular school or classroom teacher contributed to student learning, as measured by standardized-test scores. Tennessee’s version is known as TVAAS. It is included as one factor in a teacher-evaluation system that was rolled out, somewhat bumpily, in the 2011-12 school year.
Under state rules, a teacher with five or fewer tested students is graded on a “schoolwide” measure, based on the progress of all students in the school. Those teachers with six or more tested pupils receive an individual value-added estimate based on those students’ progress.
In the case of plaintiff Mark Taylor, an 8th grade science teacher, the value-added score was based on just the 22 students in his regular science class. They represented fewer than 16 percent of the total number of students he instructs, because he also has four sections of students who take an advanced course that does not conclude with a standardized exam.
The union says that the state has “no rational basis” for basing the measurement on only a fraction of a teacher’s students, and that the “arbitrary and irrational” categorization of teachers into groups with different evaluation rules violates teachers’ due-process and equal-protection rights under the U.S. Constitution.
In an interesting wrinkle, the lawsuit cites as evidence comments made by the developer of TVAAS, the North Carolina-based researcher William Sanders. Mr. Taylor’s parents were apparently acquainted with Mr. Sanders through Sunday school classes, and queried him by email whether TVAAS results based on one course were appropriate to use for evaluation purposes.
“For an overall evaluation of the effectiveness of the teacher to facilitate student academic progress, of course not,” Mr. Sanders replied, according to copies appended to the complaint.
Tenn. Teachers’ Union Takes Evaluation Fight Into the Courtroom - Education Week
Let me emphasize this part: “For an overall evaluation of the effectiveness of the teacher to facilitate student academic progress, of course not,” Mr. Sanders replied, according to copies appended to the complaint.”
OF COURSE NOT!!!!!!!!!