As for the triadic patent families and the data used, please click here (Japanese).

Triadic patent families are derived from patent applications to the EPO and the JPO, and patent granted by the USPTO, which share one or more priorities. A common approach is to calculate patent filings from a particular patent office. While the richness and strength of that indicator is broadly recognized, it is affected by “geographical location bias” and “home advantage bias” – domestic applicants tend to file more patents in their home country compared to foreign applicants. It is said that the number of triadic patent families is an appropriate indicator that can show the valuable patents circulated internationally, without such bias. For more information, please refer to the OECD website here.