A study of diagrammatic ink in lecture

In this paper, we present a study of how instructors draw diagrams in the process of delivering lectures. We are motivated by wanting to understand challenges and opportunities for automatically analyzing diagrams, and to use this to improve tools to support the delivery of presentations and the viewing of archived lectures. The study was conducted by analyzing a large group of examples of diagrams collected from real lectures that were delivered from a Tablet PC. The main result of the paper is the identification of three specific challenges in analyzing spontaneous instructor diagrams: separating the diagram from its annotations and other surrounding ink, identifying phases in discussion of a diagram, and constructing the active context in a diagram.