Two-thirds of news stories that discussed suicide and the holiday season last winter perpetuated the false belief that suicides rise during the holidays, finds a new analysis from the University of Pennsylvania’s Annenberg Public Policy Center.

Journalists often make mistakes when reporting on data such as opinion poll results, federal jobs reports and census surveys because they don’t quite understand — or they ignore — the data’s margin of error.

Over the past year, public school teachers in different parts of the country have held strikes to increase salaries and push for other changes. Such protests often mark a breakdown in negotiations between the school district and local teachers union.