= Hierarchical keywords =

|| '''Date''' || 2009/12/14 ||
|| '''Contact(s)''' || Michael Stegherr ||
|| '''Last edited''' || [[Timestamp]] ||
|| '''Status''' || draft ||
|| '''Assigned to release''' || to be determined ||
|| '''Resources''' ||  ||

== Overview ==

Currently keywords appear in a flat structure. It should be possible to create a first level keyword 'Geophysics' and a second level keyword 'DayLST' depending on the keyword 'Geophysics', both of them appear at the same level in the search box. Right now we enter the keywords as 'Geophysics | DayLST' but it means we cannot search on the 'Geophysics' keyword. It would be nice to have the possibility to search the keywords by level as displayed on the pictures below:

[[Image(Keywords_now.jpg)]] [[Image(Keywords_improved.jpg)]]

=== Proposal Type ===
 * '''Type''': GUI Change, Module Change
 * '''App''': !GeoNetwork
 * '''Module''': Search Interface

=== Links ===
 * '''Documents''':
 * '''Email discussions''':
 * '''Other wiki discussions''':

=== Voting History ===
 * Vote proposed by X on Y, result was +/-n (m non-voting members).

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== Motivations ==
The motivations for this change are:

 * Less entries in search -> less confusion
 * Search for broader terms, which include second-level keywords possible
 * If necessary or too many results, drilling down to detail possible

== Proposal == 
The current thesaurus manager is storing keywords in SKOS/RDF format, which allows creating term relationships (e.g. skos:broader, skos:narrower, etc) between keywords.

These relationships can be used to create a hierarchical structure between the keywords and list them according to this in the search interface.

Further development can include using web service based thesauri instead of local ones.

=== Backwards Compatibility Issues ===

== Risks ==

== Participants ==
 * As above