Dr. Hornof's research is in human-computer interaction. He is interested in making computers easier for people to use and learn, in finding new ways for people to use computers, and in supporting patterns of human creativity and expression. He has active research projects in cognitive modeling, eye tracking, and assistive technology.
In Dr. Hornof's cognitive modeling research, he builds computer programs that simulate the human perceptual, cognitive, and motor processes that people use when interacting with a computer. The models incorporate, for example, the cognitive strategies that people use to find something on a computer screen, or to coordinate between two different tasks on a computer, or to use 3D audio cues assist a person in coordinating multiple tasks. The modeling work is useful to user interface designers because it can help them to understand how a person is likely to use a computer interface to accomplish a task. Cognitive modeling provides a scientific and engineering base to assist a designer in improving computer interfaces.
Dr. Hornof uses eye tracking to evaluate and improve the accuracy of the cognitive models he develops. Most human-computer tasks involve some sort of eye movements, and the eye movements observed in an eye tracking experiment can show whether a model accurately simulates how people would do these tasks. For example, eye tracking can show whether a model accurately predicts how people skip over web page links of a certain color, such as links that are colored red to indicate that they have already been visited.
Dr. Hornof also uses eye tracking for real-time input to a computer, to permit creative expression through eye movements, for two different target audiences. The first audience is children with severe motor impairments, for whom Dr. Hornof has developed EyeDraw, software that is now distributed with a commercial eye tracker and enables children with disabilities to draw pictures by just moving their eyes. The second audience is new media artists and musicians, with whom Dr. Hornof collaborates to develop eye-controlled compositions that have been performed at leading international computer music conferences.
Dr. Hornof's research on assistive technology explores the difficult challenge of collaborating with children with severe disabilities, working directly with these children as partners in participatory design activities to develop systems that meet these children's developmental, communication, and creative needs.