Sheri G. Lederman NYC teacher effectiveness assessment

A teacher evaluation system used by New York State awarded an experienced and highly regarded primary school teacher one point out of twenty for her students' progress on state tests, deeming her ineffective. 

The decision led to the system being thrown out by New York highest court after primary school teacher Sheri G Lederman had sued the state for using the 'arbitrary' and 'capricious' Growth Measures system to rate teachers. 

According to the New York Times, Ms. Lederman’s students had performed marginally lower on their English exam in the 2013-2014 school year than in the previous year, causing her test-based effectiveness rating to drop from 14 out of 20 points to 1 out of 20 points. 

The 'Value Added Modeling' method was meant to account for the various factors that might impact a student’s score on a standardised test, isolate the teacher’s 'value-added' input on the student’s growth during one year of instruction, and determine whether or not the student learned as much as similarly situated students. 

The judge determined that New York State failed to make a clear case for explaining how Lederman’s score could so wildly swing in a single year.