How to Search with an Ontology Service

The Ontology search option may or may not be present in the geoportal. It is a customization that allows users to leverage an ontology service when searching from the geoportal search page. An ontology associates terms with a specific technical meaning that can be unique to your organization. The geoportal does not include tools to develop an ontology service, but does provide a simple OntologyService web application based on the GEMET thesaurus as a sample that can be integrated with the geoportal. This web application requires a keyword as an input and produces a lucene query as an output. For more information or updates on the GEMET thesaurus, please see http://www.eionet.europa.eu/gemet/about. For more information on how to configure the Ontology Service customization for a geoportal, see Enable Search Using an Ontology Service.

To search the geoportal using an ontology service, follow the steps below.

1. Launch the geoportal.
2. Click on the Search tab.
3. Type the name of the ontology service in the search blank (by default, this service will be titled "like"), then a pipe character, and then the term you want to search for in the ontology service. Example: like|river
4. Click the Search button.
5. The geoportal will reference the ontology service to not only find resources that contain the search term, but also resources with the terms associated with that search term through the ontology service. For example, searching for river not only returns resources with the word river but also delta, estuary, waterfall, and more.
6. The geoportal transforms the search term into a Lucene syntax query (see Using Lucene Search Text Queries). This means that all the rules of the lucene search syntax apply. If you want to query field names for a term, such as title or abstract, you can change the query, for example: title:like|river. Here, the term river will be processed by the ontology service named like, and then the outcome lucene syntax query will be applied to only the field title.

Note: If you are using federated search to search other catalogs from the geoportal, the ontology service cannot be used for searching those catalogs. In that case, no results will be returned if the like:term syntax is used.