By Dennis Crouch
The chart below shows the grant rate of US patent applications grouped by technology center sub-groups (technology area). The numbers come from a random set of 10,000 published patent applications that were filed between 2003 and 2010. Later-filed applications cannot be readily used for this exercise because most of them are still pending. The grant rate is calculated simply by counting the percentage of applications that have as patents. The areas of technology are shown with a representative technology-center (or art unit). Overall the grant rate in this population was 60%. I have also added error-bars showing the 95% CI for each group.