All the evidence to date shows that value-added techniques are
being employed responsibly In one suburban school district,
teachers across the system were ranked and evaluated according
to the contribution they had made to student learning–based on a
value-added analysis of state test results. When they were
ranked again the next year, the results were very similar except
for one teacher who moved from a top rank to a very low rank.
When the school superintendent looked at the results, he
immediately identified the teacher–her husband had died during
the second year of rankings. What does this anecdote illustrate?
For starters, that value-added assessments can misidentify good
and bad teachers–and that the discrepancies can be cleared up by
local administrators. More important, however, was the fact that
the findings were robust; teachers’ rankings were similar across
three years of analysis. Moreover, these rankings were used to
grant a standard reward to a top group of teachers, not to make
fine distinction