## 4 Results and Discussion
### Rq3: What are the most widely used patent data collections?
* TREC The TREC ([[https://trec.nist.gov/overview.html](https://trec.nist.gov/overview.html)]([https://trec.nist.gov/overview.html](https://trec.nist.gov/overview.html)) URL (accessed on 29 March 24)) (Text Retrieval Conference), initiated in 1992 and jointly sponsored by the National Institute of Standards and Technology (NIST) and the United States Department of Defense, is a widely recognized forum for evaluating information retrieval methods. Specifically, the TREC-CHEM track focuses on chemical patent retrieval to promote and stimulate research on chemical datasets. Table S4 in Section S3.2 of the Supplementary Material elaborates on patent retrieval-related tasks in TREC-CHEM 2009, TREC-CHEM 2010, and TREC-CHEM 2011 [8; 131; 132; 133]. Two studies [58; 75], reported to have utilized the TREC dataset. EPO  
The EPO ([[https://www.epo.org/en](https://www.epo.org/en)]([https://www.epo.org/en](https://www.epo.org/en)) URL (accessed on 29 March 24)) (European Patent Office), set up in 1973, is an international organization with 39 member states that is responsible for granting patents in Europe. EPO applications must be submitted in English, French, or German [134]. The EPO provides a valuable source of patent data for researchers to perform tasks related to patent retrieval and analysis, with the EPO dataset including only patents granted by the European Patent Office (EPO) since 1978 [135]. Studies such as those in references [88; 117] have utilized the EPO dataset; reference [88] utilized a subset of EPO patents consisting of two million English, one million French, and one million German patents, each indexed individually for claims and descriptions, while reference [117] analyzed over a million patent applications filed with the European Patent Office (EPO) between 1982 and 2005, in conjunction with more than 20 million PubMed documents published before the beginning of 2011. Google Patents ([[https://patents.google.com/](https://patents.google.com/)]([https://patents.google.com/](https://patents.google.com/)) URL (accessed on 29 March 24)) provides both a search engine and public datasets, allowing users to browse and search an extensive repository of patent-related information. The Google Public Patent Database provides a huge warehouse of patent-related data and information for in-depth research and analysis and includes patents issued by 17 different patent offices, including the United States Patent and Trademark Office (USPTO) and the European Patent Office (EPO). Moreover, it features interlinked database tables to enable data-driven investigations of patent analysis and retrieval-related tasks [136]. Five studies [60; 61; 111; 115] have utilized Google Patents. Chinese patents are managed and granted by the China National Intellectual Property Administration (CNIPA ([[https://english.cnipa.gov.cn/](https://english.cnipa.gov.cn/)]([https://english.cnipa.gov.cn/](https://english.cnipa.gov.cn/))) URL (accessed on 29 March 24)). These patents are accompanied by datasets that provide significant information for research and analysis. CNIPA datasets include bibliographic information, publishing data, and legal data for patents, utility models, and designs from 1985 to the present. Moreover, documents can be searched using a range of search parameters, such as application number, publication number, publication date, applicant or patent holder, priority, patent agency, class, title, and abstract [137]. Only one study [121] has utilized the Chinese patents. The IBM Almaden ([[https://research.ibm.com/labs/almaden](https://research.ibm.com/labs/almaden)]([https://research.ibm.com/labs/almaden](https://research.ibm.com/labs/almaden)) URL (accessed on 29 March 24)) provides a collection of more than 13 million patents stored in an Oracle Database Management System for Novartis, as part of a collaboration project between Novartis/NIBR-IT and IBM. These patents, which cover various application areas associated with life and health sciences, can be retrieved using SQL queries and are stored in an XML format.