Dr. Gauthier is on the faculty of a large research university. She is interested in how different views of source code influence program understanding and has therefore built a tool that offers a data flow view, a control flow view, and an architectural view of a system. She wants to see which of the different views help software engineers design and maintain source code more effectively. Unfortunately, Dr. Gauthier does not have access to industrial software engineers to test her tool. Consequently she decides to use the students in her software engineering class as test subjects. She divides the students into four sections. Each of three sections is given one of Dr.Gauthier’s tools with a different view. The fourth section uses the standard tools provided by the university programming environment. Dr. Gauthier gives all four sections the same midterm project. She finds that some of views offer modest gains in productivity.