Taxonomies, Ontologies, and Metadata

Taxonomies and Ontologies

What’s the difference between a taxonomy and an ontology? This is a question we get asked regularly, and having built a great many taxonomies and several ontologies, we’re in a good position to help you understand what the difference really is, and to work with you to discover what you actually need for your organisation.

Do you want to improve findability by providing controlled lists of tags, synonyms or filters? Will tags be added to content manually or via autocategorisation? Do you want to automatically assign retention and disposal schedules? Are you interested in entity extraction? Could your users get real benefit from the rich relationships and inferencing that an ontology could offer, or do you just need a simple browse structure?

We understand how important it is create the right tool for the job, and to exploit the benefits of a taxonomy or ontology to their fullest extent to give real value for money. We have many years’ international experience of developing these kinds of semantic structures, and of running university, public and inhouse courses.


Balancing the need for accurate metadata to manage, find and use your information against the issues inherent in getting that metadata applied is tricky. The key is to recognise which metadata values can realistically be captured for your content, and whether this can be done automatically (for example via templates or autocategorisation software), or whether the tags have to be added manually.

Of course metadata can be applied not just at the document level, but also at other levels of granularity, from whole collections to a single paragraph, image or tweet, and different types and formats of content need different metadata elements (fields). Whatever that level of granularity is, it will be important to take a holistic view of your metadata schema to ensure that its use is consistent and fully exploited across the organisation.

Part of the process is also to identify sets of controlled vocabularies which would support the metadata model. This may in the building of a taxonomy or ontology to tag the content and ultimately deliver a richer search experience to your users.

Metataxis has devised metadata models, taxonomies and ontologies for government, NHS, third sector and commercial clients. We can advise on what the metadata should be, and what the most efficient ways of capturing it will be. If required, we can even provide people to do the tagging for you in order to take the burden off in-house staff.

Metataxis provides public and in-house training courses in metadata, and also in taxonomy, thesaurus and ontology development.