The PROMIS cooperative group comprises six Primary Research Sites (PRS) and a Statistical Coordinating Center (SCC) working in collaboration with project scientists at the National Institutes of Health (NIH). Each PRS is funded to participate in the network and to contribute independent scholarly research to explore innovative ideas and to test novel strategies of data collection. Each PRS is designed to address the needs of the overall PROMIS network. Hence, the independent research projects interact with and inform the overall objectives of the PROMIS cooperative group.