Below are some more resources that may help you with your decision.
NY State Exams: Quiz for Parents
Principal: There comes a time when rules must be broken...That time is now
Carol Burris, The Washington Post, February 19, 2015
Ginia Bellafante, NY Times, March 28, 2014
"This movement of refusal does not evolve out of antipathy toward rigor and seriousness, as critics enjoy suggesting, but rather out of advocacy for more comprehensive forms of assessment and a depth of intellectual experience that test-driven pedagogy rarely allows. In the past year, the movement has grown considerably among parents and educators, across political classifications and demographics."
11 problems created by the standardized testing movement
ChangetheStakes.org has a wealth of resources that can help inform your decision:
Why Opt Out of New York State standardized tests?
How to Opt Out of State Standardized Tests
Why My Family is Opting Out of the Common Core Testing
Karen Klein, LA Times, April 8, 2014
"Opting out has occurred to me before, but that seemed selfish. The idea of the tests is to look at the larger picture of how much progress the schools, the districts and the state are making. Participation was the socially responsible thing to do. (...) I'm not one for whining about standardized tests. (Not until now, anyway.) They have certain, limited uses. At their best, the state tests could be used to guide better teaching; at their worst, they are used as the main measure of educational quality. They're an imperfect fact of life, and one of the important lessons students get out of public schools is that life is not perfect. We deal with it."