CLARIN Virtual Language Observatory: Help

Search syntax

In addition to navigating the resources by means of the selection of facet values, the VLO faceted browser also allows for searching by means of textual queries.

Such queries are to be entered in the large text box at the top of the main page or faceted browsing page with the button labeled 'Search' next to it.

In its simplest form, a search query consists of one or more terms, separated by a space character. Such queries result in the retrieval of all documents that have one or more occurrences of all of the included search terms. In other words, an AND operator is implied by default.

Advanced querying

It is possible to construct a more specific query by means of a set of syntax features that can be processed by the VLO. The supported syntax is that of the Lucene Query Parser 1

The Lucene Query Parser syntax allows for the following boolean operators: 'AND', 'OR', 'NOT', '+' and '-'. It also allows for grouping of terms by means of parenthesis. Terms can be combined into phrases by means of double quote characters.

The following examples illustrate the usage of these operators. Click any of the following examples to perform that query on the actual data currently in the VLO:

Targeting fields

In addition to the logical operators, the syntax also allows for search for occurrences of a term within a specific field, such as language or modality. To do so, enter the name of the field and the term to search for, separated by a semicolon. The asterisk ('*') can be used to achieve partial matches. Quotes are required to match a term that contains spaces.

The following field names are available: language, country, continent, modality, genre, subject, format, organisation, resourcetype, keyword, resources.

Click any of the following examples to perform that query on the actual data currently in the VLO:

A full overview of syntax features, including options for fuzzy search, ranges, and term boosting, can be found at the Lucene syntax description page.

Notes

1 Support for the Lucene syntax was implemented by using the Solr Extended DisMax Query Parser.