Pew Research Center is a nonpartisan, nonadvocacy fact tank that informs the public about the issues, attitudes and trends shaping the world.

While small dogs have a reputation for being somewhat feisty, tiny canines are increasingly appealing to an active, educated, and urban generation. Small dogs are generally more manageable than their ...

Real-world optimization problems often require an external “modeling engine” that computes fitnesses or data that are then input to an objective function. These programs often have much longer ...