Aaron Pallas, a sociologist at Teachers College, is a sharp observer of educational issues.

In this article, he comments on a joint statement by the leaders of education in New York City and State, hailing the Common Core and the new Common Core tests. Their article appeared in the New York Daily News, where they proclaimed the advent of the new standards and the joy they are bringing back to learning. And now the new Common a core tests will let everyone know whether our none-year-olds are college-and-career-ready.

For most parents of young children, this is doubtless a burning issue, especially since no one can be sure what careers will exist 10 years from now.

What did they forget to say: the introduction of new tests means there is no trend line, no way of basing teacher evaluations on scores. Pallas writes, in part, supplying his own version of the text that wasn’t there:

“Because this year’s assessments are a completely different baseline than previous state assessments, it would be inappropriate to treat the difference between last year’s scores and this year’s scores as evidence of student growth in achievement. Therefore, we are suspending the use of student growth percentiles and value-added models to estimate teachers’ contributions to their students’ learning as a required element of the Annual Professional Performance Review of teachers and principals across New York state for at least one year.”