Model Bots, not Humans on Social Media.

The Posting schedule reveals characteristic patterns of users on social media. Motivated by this knowledge, several researchers have modeled posting schedules and argued that deviation from the model indicates bot or spammer characteristics. It is true that circadian rhythms induce regularity in human posting behavior; however, in this paper, we show that this regularity is an individual trait and insufficient to develop a generic model. More surprisingly, we show that bots are more structured in their posting behaviors compared to humans by using a Convolutional Neural Network (CNN). More precisely, we demonstrate using Class Activation Maps that bots contain less entropy than humans. Thus, we conclude that bots are more amenable to generic models than humans. We evaluate the hypothesis on more than 32 million posts from 12 thousand Twitter users with 97% accuracy.