This document discusses using an issue hierarchy approach to prioritize issues found during research. It presents an issue hierarchy pyramid with the following levels from bottom to top: 1) Technical Performance, 2) Player Requirements, 3) Usability, 4) Motivation, 5) Fun. It explains that lower levels must be addressed before higher levels for improvements to be effective. For example, a game cannot be fun if it crashes or players do not understand how to play. The hierarchy also informs the type of research needed at each level.