# PatentInspector: An Open-Source Tool for Applied Patent Analysis and Information Extraction
## 7 Threats to Validity  
In this section, we present some threats to the validity of the proposed PA software (v.1), making the distinction between internal validity, i.e., limitations in the methodological design of PatentInspector, and external validity, i.e., factors that limit the generalization and applicability of PatentInspector to other domains or patent offices. Regarding internal validity, one primary limitation is that PatentInspector only retrieves data from the USPTO and not from other major patent offices, such as the EPO or CNIPA. This automatically skews the results, as the illustrated plots, topics and citation networks will inevitably present a partial view of patent grants, with a focus on the US region. However, this threat is mitigated by the fact that the USPTO has been indicated in the literature to be a viable source that effectively captures global patent trends [111; 117]. It should also be emphasized that the choice of the USPTO was based on the fact that it was the only patent office to include a \"bulk data\" endpoint that could allow the storage of the entire patent office in the database of PatentInspector, given the resources and limitations to access and real-time data retrieval when developing the tool. We recognize that this is a threat and plan to expand the tool to include more data sources in subsequent versions. In addition, the developed tool leverages data from patents that have already received a grant and does not consider patents that have been applied for and are pending evaluation. While this may lead to data omission, it is a reasonable practice, as applied patents may be rejected, in contrast to granted patents that have been carefully examined. In addition, a minor threat to the developed tool is that we do not introduce new methodologies for PA or leverage advanced methodologies for strategic analysis, technology convergence or business scoping. However, as our primary goal was to introduce a PA tool accessible to multiple parties with various backgrounds, the features that were chosen and incorporated focused on scientific concepts that can be easily understood and interpreted by individuals of different levels. In terms of our reliance on user judgement and expertise, this only has relevance when experimenting with the implemented topic analysis algorithms. An experienced user can alter the values of topic modeling (number of models, keywords to be removed, time range) and experiment with different setups. However, we consider this a minor threat, as the topic modeling aspect of PatentInspector is fully supported to run on the default parameters and produce reliable results. Finally, as far as the waiting times for the analysis to be conducted are concerned, this is indeed a limitation in the functionalities of PatentInspector, as the deployed server cannot support a large number of simultaneous users. To mitigate this, we have implemented an alert function that allows users to exit the tool, run the analysis in the background and receive an email once the report is generated. Regarding the external validity of PatentInspector, the applicability of our data retrieval, preprocessing, storage and analysis could potentially extend to other patent offices but it may be hindered both by closed and proprietary APIs, as well as possible different patenting procedures, which may lead to different data being stored. Thus, any application of our tool to another office, such as the EPO, should be carefully structured, with proper adjustments to the database in order to accommodate potentially varied patent data. In addition, as PatentInspector relies on predomoaded data from USPTO that are periodically updated, it cannot be used as a patent database that retrieves data \"on the fly\", but rather as a tool for analysis that utilizes the most recent snapshot of patent data from the USPTO.