About Us

Class Size Matters is a 501C3 non-profit organization that advocates for smaller classes in NYC’s public schools and the nation as a whole.  We also advocate for greater parent involvement in decision-making and for strengthening student privacy protections.

Check out the Parent Coalition for Student Privacy website for more information on student privacy.

You can make a tax-deductible donation to either Class Size Matters or PCSP by clicking here.  

Our EIN is: 20-2169746

You can  subscribe to our Class Size Matters newsletter here and follow us on twitter at @classsizematter and @leoniehaimson

You can also send a check or contact us at the address below:

Class Size Matters, 124 Waverly Pl., New York, NY 10011.
info@classsizematters.org;  917-435-9329.

The New York Times has called us the “city’s leading proponent of smaller classes.”  We are dedicated to providing information on the significant and wide-ranging benefits of smaller classes, particularly for at-risk children, to boost student learning, engagement, and graduation rates, and lower disciplinary referrals.

We also advocate for alleviating school overcrowding, and work for more parent decision-making in the area of education policy, including the ability of parents to protect their children’s privacy and control the disclosure of their personal student data.

The organization’s founder and Executive Director, Leonie Haimson, was a public school parent for 15 years.  She received the John Dewey award from the United Federation of Teachers in 2007, was named one of NYC’s “family heroes” by NYC Family Magazine in 2009, and was honored as an “Extraordinary Advocate for our Children” by Advocates for Justice in 2012.

In 2014, she received the “Parent Voice” award from Parents Across America for her work defeating inBloom and protecting student privacy.  In 2015, she was named one of the ten most influential people in education technology by Tech and Learning Magazine. In 2020 and 2021, she was named the 16th most powerful education leader in New York State by City and State magazine.

Leonie co-founded and co-chairs the Parent Coalition for Student Privacy [PCSP],  which is a project of Class Size Matters.  PCSP has released two toolkits, one for parents and one for educators , on how to better protect student privacy.  The Coalition has also been invited to testify before Congress twice in recent years on how federal student privacy law should be strengthened.  She also sits on the board of the Network for Public Education.

She has appeared on CNN, Fox News, MSNBC, Good Day NY, WNBC News, National Public Radio, Al Jazeera, Democracy Now, NY1, Bob Herbert’s Op-Ed.TV and numerous other television and radio shows. She has written for the NY Times, the Nation, Education Week, Washington Post, the Indypendent, SchoolBook, Huffington Post, Chalkbeat, In These Times, Gotham Gazette, City and State, and  other publications. She blogs at NYC Public School Parents . 

A copy of our most recently filed financial report is available from the Charities Registry on the New York State Attorney General’s website or, upon request, by contacting the New York State Attorney General, Charities Bureau, 28 Liberty Street, New York, NY 10005.