Figure 8. How average error per observation affects uncertainty about the "true" average performance Methodological Considerations in Generating Provider Performance Score Return to Document Current as of September 2011 Internet Citation: Figure 8. How average error per observation affects uncertainty about the "true" average performance: Methodological Considerations in Generating Provider Performance Score. September 2011. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/professionals/quality-patient-safety/quality-resources/value/perfscoresmethods/perfscfig8.html