It's not spam to discuss an important community issue in the letters section. After all we are also SA subscribers and are posting our letters in here as well.

A lot of the criticism in the literature is bad. And in professional journal the original preschool researchers were given a chance to respond in the addendum of a published review paper on preschool research. Here the response of the Perry researcher. 

http://www.welfareacademy.org/pubs/early_education/pdfs/Besharov_ECE%20assessments_Perry_Preschool.pdf

"While fair criticism is essential to the scientific method and the advancement of knowledge, unfair criticism undermines the scientific method and presents unhelpful information masquerading as knowledge...  In a good story that may even be true, B. F. Skinner is said to have retorted to a persistent questioner, “Science progresses by standing on the shoulders of those who have gone before. But you sir, are standing on my feet.”