ROC comment: automated descriptive and subjective captioning of behavioral videos

We present an automated interface, ROC Comment, for generating natural language comments on behavioral videos. We focus on the domain of public speaking, which many people consider their greatest fear. We collect a dataset of 196 public speaking videos from 49 individuals and gather 12,173 comments, generated by more than 500 independent human judges. We then train a k-Nearest-Neighbor (k-NN) based model by extracting prosodic (e.g., volume) and facial (e.g., smiles) features. Given a new video, we extract features and select the closest comments using k-NN model. We further filter the comments by clustering them using DBScan, and eliminating the outliers. Evaluation of our system with 30 participants conclude that while the generated comments are helpful, there is room for improvement in further personalizing them. Our model has been deployed online, allowing individuals to upload their videos and receive open-ended and interpretative comments. Our system is available at http://tinyurl.com/roccomment.