While VAMs have many issues pertaining, fundamentally, to their levels of reliability, validity, and bias, they are wholeheartedly unfair. This is one thing that is so very important but so rarely discussed when those external to VAM-based metrics and metrics use are debating, mainly the benefits of VAMs.
Issues of “fairness” arise when a test, or more likely its summative (i.e., summary and sometimes consequential) and formative (i.e., informative) uses, impact some more than others in unfair yet often important ways. In terms of VAMs, the main issue here is that VAM-based estimates can be produced for only approximately 30-40% of all teachers across America’s public schools. The other 60-70%, which sometimes includes entire campuses of teachers (e.g., early elementary and high school teachers), cannot altogether be evaluated or “held accountable” using teacher- or individual-level VAM data.
Put differently, what VAM-based data provide, in general, “are incredibly imprecise and inconsistent measures of supposed teacher effectiveness for only a tiny handful [30-40%] of teachers in a given school” (see reference here). But this is often entirely overlooked, not only in the debates surrounding VAM use (and abuse) but also in the discussions surrounding how many taxpayer-derived funds are still being used to support such a (purportedly) reformatory overhaul of America’s public education system. The fact of the matter is that VAMs only directly impact the large minority.
While some states and districts are rushing into adopting “multiple measures” to alleviate at least some of these issues with fairness, what state and district leaders don’t entirely understand is that this, too, is grossly misguided. Should any of these states and districts also tie serious consequences to such output (e.g., merit pay, performance plans, teacher The Elephant in the Room – Fairness | VAMboozled!: