ICSM ISO19115-1 Metadata Best Practice Guide

Coupling Type ★★★★

When documenting a service, the nature of the relationship of the service to the data resources on which it interacts is important to capture to provide potential users with an understanding of the applicability of such service to their needs. A service may be highly dependant on particular data, independent of the data or a mixture.

   
Element Name couplingType
Parent MD_Metadata.identificationInfo>SV_ServiceIdentification
Class/Type codelist - SV_CouplingType
Governance Domain, Agency
Purpose Evaluation, Use
Audience machine resource - ⭑ ⭑ ⭑
  general - ⭑ ⭑ ⭑
  resource manager - ⭑ ⭑ ⭑ ⭑
  specialist - ⭑ ⭑ ⭑
Metadata type structural
ICSM Level of Agreement ⭑ ⭑

Definition

The type of coupling between service and associated data (if exists)

ISO Requirements

There must be zero or one [0-1] couplingType entries for the cited resource for a SV_ServiceIdentification package selected from the codelist SV_CouplingType in a metadata record. If a coupled resource exists, this element must be populated.

Discussion

The relation of a geospatial service to the data on which it operates is varied. This relation impacts the decisions one may make regarding the capture of useful metadata for such a service. These services fall into three categories depending on how tightly coupled the data is to the service: tightly, loosely, or mixed.

An example of a tightly coupled service would be a WFS service delivering a particular dataset. In the tightly coupled case, the service metadata shall describe both the service and the geographic dataset. The permitted values for the description of operations shall be constrained by the values defined by the datasets associated with the service.

An example of a loosely coupled service could be a reprojection service with user-selected input datasets. Loosely coupled services may have an association with data types through the service type definition (SV_ServiceIdentification.serviceType). Dataset metadata need not be provided in the service metadata for the loosely coupled case.

A mixed coupling might be a WMS service into which you may add additional data sources of your choice. In a mixed coupling situation a single service instance may be associated with both kinds of data associated, loosely and tightly coupled.

ICSM Best Practice Recommendations

Therefore - the element couplingType should be populated in all service metadata records. If the Coupling Type is tight then the coupled resource element must be populated for all coupled resources.

Values for Codelist SV_CouplingType

From codelist - SV_CouplingType. Available values for SV_CouplingType are:

Examples

GA

{example - if any useful}

ABARES

{example - if any useful}

Others

{### who - example - if any useful}}

XML -

<mdb:MD_Metadata>
....
 <mdb:identificationInfo>
   <srv:SV_ServiceIdentification>
    <mri:citation>
    ...
    </mri:citation>
    <mri:abstract/>
    <srv:serviceType>
      <gco:ScopedName>view</gco:ScopedName>
    </srv:serviceType>
    <srv:couplingType>
      <srv:SV_CouplingType codeList="http://standards.iso.org/iso/19115/resources/Codelists/cat/codelists.xml#SV_CouplingType"
                codeListValue="tight"/>
    </srv:couplingType>
    <srv:coupledResource>
     ....
      </srv:SV_CoupledResource>
    </srv:coupledResource>
    <srv:containsOperations>
    ....
    </srv:containsOperations>
   </srv:SV_ServiceIdentification>
 </mdb:identificationInfo>
....
</mdb:MD_Metadata>

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UML diagrams

Recommended elements highlighted in yellow

Coupling Type

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