Re: ANN: Modular Unified Tagging Ontology (MUTO)

On 17.11.2011 20:03, Richard Cyganiak wrote:
> Hi Steffen,
> On 17 Nov 2011, at 14:34, Steffen Lohmann wrote:
>> MUTO should thus not be considered as yet another tagging ontology but as a unification of existing approaches.
> I'm curious why you decided not to include mappings (equivalentClass, subProperty etc) to the existing approaches.

Good point, Richard. I thought about it but finally decided to separate 
these alignments from the core ontology - therefore the "MUTO Mappings 
Module" (

SIOC and SKOS can be nicely reused but aligning MUTO with the nine 
reviewed tagging ontologies is challenging and would result in a number 
of inconsistencies. This is mainly due to a different conceptual 
understanding of tagging and folksonomies in the various ontologies. To 
give some examples:

- Are tags with same labels merged in the ontology (i.e. are they one 
- Is the number of tags per tagging limited to one or not?
- In case of semantic tagging: Are single tags or complete taggings 
- How are the creators of taggings linked?
- Are tags from private taggings visible to other users or not?

Apart from that, I would have risk that MUTO is no longer OWL Lite/DL 
which I consider important for a tagging ontology (reasoning of 

The current version of the MUTO Mappings Module provides alignments to 
Newman's popular TAGS ontology (mainly for compatibility reasons). Have 
a look at it and you'll get an idea of the difficulties in correctly 
aligning MUTO with existing tagging ontologies.


Steffen Lohmann - DEI Lab
Computer Science Department, Universidad Carlos III de Madrid
Avda de la Universidad 30, 28911 LeganÚs, Madrid (Spain), Office: 22A20
Phone: +34 916 24-9419,

Received on Friday, 18 November 2011 10:25:43 UTC