Her research focuses on the psychology of media effects with an emphasis on the effects of exposure to media violence. Most recently, she has explored media violence vividness, including the effects of violence that is graphic, explicit, and memorable. She is a contributing author on a content analysis project assessing modern portrayals of violence on American television. Riddle also runs the Video Game Research Group, which designs and conducts research on video game effects and is the Director of Graduate Studies in the SJMC.