Special page "PropertyLabelSimilarity"

From semantic-mediawiki.org
Lists syntactic similarities between property labels
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Further Information
Provided by: Semantic MediaWiki
Added: 2.5.0
Removed: still available
In this wiki: Special:PropertyLabelSimilarity
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PropertyLabelSimilarity is a special page that lists syntactic similarities between properties. The special page was introduced in Semantic MediaWiki 2.5.0Released on 14 March 2017 and compatible with MW 1.23.0 - 1.29.x..1


Before this special page displays the results of the property similarity evaluation on the wiki the user has make two choices which control the selection and the display of the property similarity evaluation:

  1. Similarity threshold field − Allows to specify the threshold used for the computation of results. In theory this is a number between "100" and "1". The default suggestion is "90" and in practice going blow "75" will not bring any benefit to the evaluation.
  2. Datatype ID checkbox − Allows to specify if the datatype should be displayed together with the property name. This is a facultative but recommended display option.


This special page shows its results per similarity finding which is split into two sections:

  1. property - displays the two properties which appear to be similar and provides further information to make an assessment easier:
    • label - displays the name given to the respective property
    • type - displays the datatype which was assigned to the property shown represented by the internal type ID
  2. similarity - displays the calculated syntactic property similarity value


This is the output of this special page for a wiki which defined the properties "Has point of interest" and "Has points of interest" both with datatype "Page" denoted by the respective "_wpg" type ID and a calculated similarity of "97.67". The threshold was set to "95" and the checkbox to display the datatype ID was ticked off.

The result shows that both properties should be migrated into one property due to its additional semantic similarity, i.e. there is no differenced between the two.

        "property": [
                "label": "Has point of interest",
                "type": "_wpg"
                "label": "Has points of interest",
                "type": "_wpg"
        "similarity": 97.67


Configuration parameter $smwgSimilarityLookupExemptionPropertySets the property used to exclude a property from being evaluated during similarity checks defines a property that allows to describe properties in terms of an exemption condition meaning to exclude a property from the process of syntactic similarity evaluation. By default this property is called "owl:differentFrom".

For example, on the property page "Governance level" one may annotate [[owl:differentFrom::Governance level of]] which would result in a suppressed similarity lookup for both properties "Governance level" and "Governance level of" property when compared to each other. Thus it is clear that these two properties "Governance level" and "Governance level of" are indeed similar but conceptually different and they will not be shown on this special page. See the respective example on the sandbox wiki.2

See also[edit]


  1. ^  Semantic MediaWiki: GitHub pull request gh:smw:2244
  2. ^  |  Semantic MediaWiki: GitHub pull request #2244 example #2