High-profile polling failures in recent elections have drawn attention to the challenges in using surveys to predict outcomes. Our study examines various methods of determining who is a likely voter.

Parents monitor their teen’s digital activities in a number of ways, such as checking browser histories or social media profiles, but using technical means like parental controls is less common.

Every year, we look back at our research to select the most memorable facts that illustrate important trends shaping our world.

• Fact Tank: Your Favorite Data in 2015