# Multi-Purpose Ontology-Based Visualization of Spatio-Temporal Data: A Case Study on Silk Heritage
## 6 Conclusions and Future Work  
In this paper, we show the STMaps tool, a multipurpose ontology-based visualization tool of spatio-temporal data. The tool has been designed to show the content of a CH project through an interactive map. This content is stored in a CIDOC CRM ontology and represents the knowledge acquired through the SILKNOW project, a research project devoted to study and promote the rich silk-related heritage of Europe. Nevertheless, although the tool has been designed within the context of silk cultural heritage, it can be used in other cultural and non-cultural contexts. STMaps provides some unique features. First, it is a multi-platform application. It can work embedded in an HTML page and can also work as a standalone application over several computer architectures, provided that data can be supplied to the application. The advantage of the web-based application is that it can be integrated within an ontology-based search web page. Thus, the web page can be used to filter the data quickly and interactively. Second, it is entirely based on ontology support as it gets the source data from an ontology (a DO) and also uses another ontology (a VRO) to define how data should be visualized. STMaps currently uses VISO (in fact, an extended version of VISO developed by the authors) as its VRO. In this regard, as the method relies on visualizing spatio-temporal data provided by an ontology using open-software, the tool could be used to visualize the results of any project even if different datasets are used, provided that these datasets contain spatio-temporal information. In addition, our tool has multi-ontology support and can be utilized even with other types of domain ontologies. Third, it provides different mechanisms to show spatio-temporal data, and also deals with uncertain and missing data. Timelines, time layers, line-based representations and ring-based representations are used in STMaps. These representations are configured through a JSON-based mechanism and can be changed. The mapping between the VRO and the properties to visualize can also be configured. Therefore, the tool can be setup to provide different visualization procedures. Finally, the SILKNOW implementation of STMaps is a unique tool, since, to the best of our knowledge, it is the first KAVT that shows spatio-temporal data of silk-related CH objects. The tool has been tested with SILKNOW's ontology over different computer architectures, exhibiting the same behavior in all of them. We have deployed and tested the application in several platforms: Windows, Mac OS, Android and iOS, with the most popular browsers: Firefox, Chrome and Edge. We have also used it to browse silk-related objects, discovering some interesting relationships between different objects, showing the versatility and power of the different visualization tools provided in STMaps. Currently, we are performing an extensive evaluation of this visualization tool and the search utilities (more information on [94]) as part of the SILKNOW project, which is expected to finish in late 2021. As future work, we will consider possible extensions or improvements based on the feedback obtained from this evaluation. We also plan to further extend VISO to add more features and/or introduce different visualization ontologies into STMaps, so that it is possible to use a VRO not based on VISO. Finally, we need to further deepen the visualization of missing, incomplete or uncertain information, testing different alternatives and assessing them. Conceptualization, C.P. and S.C.-Y. ; methodology, J.S., C.P. and S.C.-Y. ; investigation of related work, S.C.-Y. and J.S. ; software, P.C.-S. and J.S. ; writing, S.C.-Y., J.S., C.P. and P.C.-S. All authors have read and agreed to the published version of the manuscript. The research leading to these results is in the frame of the \"SILKNOW.