In a previous posting, we identified the most difficult examiners at the USPTO based on allowance rate. Due to the intense amount of interest that post generated, we decided that we would take our study a step further by measuring the most difficult art units at the USPTO, also based on allowance rate. Due to the reality that two examiners in the same art unit can have wildly differing allowance rates, this measurement is not as “pure” as measuring allowance rates at the individual examiner level. However, an art unit’s average allowance rate does give practitioners at least some idea of how difficult getting an allowance in that art unit is likely to be. 

Below, we’ve ranked the ten most difficult art units (measured by allowance rate) in the entire USPTO. We limited our pool of eligible art units to utility art units where at least 100 applications have been disposed since 2004. Hover over the graph for detail.

The average allowance rate for all art units at the USPTO is about 72%. For the bottom ten art units that we identified, the allowance rate ranges from 10.0% in art unit 3689 to 34.2% in art unit 1757. Combined, the bottom ten art units have an average allowance rate of about 28%, which is about 62% below the USPTO average. 

When looking at the tech centers where the art units are found, we noticed a change from our previous article. While fully half of the top 10 most difficult examiners at the USPTO are found in the e-commerce art units of TC 3600 (as is to be expected), over half (60%) of the most difficult art units are found in TC 1600, home to biochemistry and organic chemistry applications. We theorize that the reason for the low allowance rates at the examiner level in TC 3600 are due to the Alice decision, while those at the art unit level in TC 1600 are due to the effects of the Myriad/Mayo decisions. Thus, the effects of the legal framework that was built in a string of cases running through Myriad, Mayo, and Alice can be felt across multiple work groups at the USPTO. 

For a visual breakdown of where these art units are found, see Figure 2 below. Hover over the graph for detail.

As bad as these numbers may seem, there is good news for practitioners working with these technologies. Big data now offers a solution to these new legal headaches by allowing patent prosecutors to see what their chances of getting an allowance are at the very beginning and explaining their strategy to their clients with confidence. To see what big data can do for your patent prosecution practice, try out of a free trial of Juristat for 7 days.


* Because art units come and go, and due to the 16-year span of the data, these art units are no longer functioning at the USPTO. They are now covered by other art units in the same work groups.