Face-to-face communication is a highly interactive process where participants mutually exchange and interpret verbal and nonverbal messages. Communication dynamics represent the temporal relationship between these communicative messages. Even when only one person speaks at a time, other participants exchange information continuously among themselves and with the speaker through gesture, gaze, posture, and facial expressions. An important challenge for artificial intelligence researchers in the 21st century is in creating socially intelligent robots and computers that are able to recognize, predict, and analyze verbal and nonverbal dynamics during face-to-face communication. This will not only open up new avenues for human-computer interactions but create new computational tools for social and behavior researchers—software able to automatically analyze human social and nonverbal behaviors and extract important interaction patterns. Learn about the challenges and proposed solutions for Modeling Human Communication Dynamics through the Social Science Column of IEEE Signal Processing Magazine (September 2010).