Four overall measures of the technical robustness of a technical community are: 1. Affiliation rate, 2. Author rate, 3. Source rate, and 4. Longevity. These four measures are determined by looking at a field of technical research as defined by keywords, concepts, or patent classifications. Once the field of art is defined, the four measures can be calculated.
The affiliation rate is defined by plotting the number of assignees occurring in patents for each filing or issue year. This trend line shows how the number of investing entities in the technology is either growing or shrinking.
The author rate is defined by plotting the number of inventors occurring in patents for each filing or issue year. This trend line shows how the inventor pool is either growing or shrinking over time.
The source rate is defined by plotting the number of patents granted or applications filed at each filing or issue year. This metric shows the maturity of the technology over time. Over longer time frames it also acts as a leading indicator to the overall market size that the technology supports.
The longevity is defined by plotting the average number of years of life remaining in all patents in the portfolio at each filing or issue year. This metric indicates the commercial level of interest in the technology area.