It was a silent call to arms: an easy-to-overlook message urging New Jersey students to take a stand against the budget cuts that threaten class sizes and choices as well as after-school activities. But some 18,000 students accepted the invitation posted last month on Facebook, the social media site better known for publicizing parties and sporting events. And on Tuesday many of them — and many others — walked out of class in one of the largest grass-roots demonstrations to hit New Jersey in years.

Attendance Court for New York City Truants

The court has no power to punish, but students and their parents get helpful advice and offers of counseling and other services.

Graduate Students Ask N.Y.U. to Recognize Union

The teaching assistants hope to persuade the National Labor Relations Board to reverse a 2004 ruling and give them the right to organize.

Advertising: Teaching Youngsters How to Read Advertising

A government campaign will try to teach children from the fourth to the sixth grades how to think critically about ads.