Users of complex software applications often learn concepts and skills through step-by-step tutorials. Today, these tutorials are published in two dominant forms: static tutorials composed of images and text that are easy to scan, but cannot effectively describe dynamic interactions; and video tutorials that show all manipulations in detail, but are hard to navigate. We hypothesize that a mixed tutorial with static instructions and per-step videos can combine the benefits of both formats. We describe a comparative study of static, video, and mixed image manipulation tutorials with 12 participants and distill design guidelines for mixed tutorials. We present MixT, a system that automatically generates step-by-step mixed media tutorials from user demonstrations. MixT segments screencapture video into steps using logs of application commands and input events, applies video compositing techniques to focus on salient infor-mation, and highlights interactions through mouse trails. Informal evaluation suggests that automatically generated mixed media tutorials were as effective in helping users complete tasks as tutorials that were created manually.

Computer Science Illustrated1 is an endeavor to help visual learners comprehend computer science topics through a series of resolution-independent illustrations, which are made available online for use as handouts in class and posters in the computer labs. These illustrations are designed to present concepts as engaging and memorable visual metaphors combined with concise explanations or short narratives, intended to maintain the students' interest and facilitate retention. An additional goal of the project is to make learning the concepts an entertaining experience through the use of colorful and whimsical characters in the illustrations. In producing our twenty-seven illustrations, we determined which topics were most difficult for students to understand in our university's introductory computer science courses and followed a step-by-step process of design, redesign, and revision to generate our illustrations. We also assessed the effectiveness of our creations, using both subjective and objective measures.