ZOOMA: Ontology Mapping for Optimized Matches

1. ZOOMA – Optimal Ontology Mapping Application Tony Burdett 29nd April

2. What is ZOOMA? ZOOMA is an ontology mapping application, designed to find optimal matches between “text values” and “ontology terms”. A bit of background: • ZOOMA grew out of the need to offer queries against EFO for data newly loaded into Atlas 2.0. • At load, user supplied text values are not resolved against ontology terms • Curators need to be able to “map” text values for newly loaded data in order to support ontology-enabled queries Master headline

3. Wider Usecase • Our pressing requirement, right now, is to map text values to ontology terms in the Atlas • But, this is a wider problem – such mappings are found in everything we do. • Atlas, ArrayExpress2, BII, MAGE-TAB, submitters all need to do this sort of ontology mapping • So it makes sense to do the mapping logic once and reuse it! Master headline

4. Some Jargon • We probably all understand what “text values” and “ontology terms” means (or we think we do) • “Text values” are things that a user, or maybe a curator has entered • This isn’t necessarily (but probably is) some sort of controlled term • “Ontology Terms” are things which come (only) from an ontology • If you can’t find it, it’s not an ontology term! • A “mapping” is an assertion that some text value somehow relates to some ontology term(s). Master headline

5. Atlas World View • The Atlas DB has Property, PropertyValue and OntologyTerm tables. • Properties are the “types” (e.g. organismpart) and Property Values are the values (e.g. heart) • These are controlled (reused between experiments) • There are join tables – AssayPVOntology and SamplePVOntology – to join property values to OntologyTerms on the assay and sample level Master headline

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7. ArrayExpress2 World View • The ArrayExpress database also has Property, PropertyValue, OntologyTerm and OntologyEntry tables. • However, they’re joined in different ways • In the Atlas, Properties and Property Values are reused, and the join table determines uniqueness • In ArrayExpress2, there are join tables to join Properties to OntologyEntries, and Property Values to OntologyTerms (basically) • This means Property and Property Values must be unique per “usage”. Master headline

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9. MAGE-TAB World View • In MAGE-TAB, certain columns can be followed with “Term Source REF” which designates a link to an Ontology Term. • The value entered into the column is a text value • The Term Source REF indicates we should be able to find an ontology term with the matching “name” in the given ontology • But this can be hit and miss! Although term source accession is better Master headline

10. MAGE-TAB World View Property (IDF may link to OntologyEntry) Property value Ontology term Master headline

11. Now that’s over… what does ZOOMA do? • In general, ZOOMA has three main modes of operation… • Automatic • This highlights any optimal mappings that don’t need curation • One text value maps to the same set of terms every time • Error detection • Highlight any mappings from text value to ontology term that might be in error • This only makes sense if you have a “repository of mappings” e.g. Atlas • Mapping suggestions • Take values, and propose new mappings to terms • Requires a curator eye to make a decision on which mapping is best Master headline

12. What ZOOMA does • These three modes are currently implemented for the Atlas, and for a list of values submitted by file • In the Atlas, ZOOMA will… • Lookup property values from Atlas (these are our text values), and find the optimal ontology term hits against EFO • Lookup property values from Atlas and find inherited ontology term hits from elsewhere in the database • Lookup property values from Atlas and find possible matches to terms not in EFO, querying BioPortal/OLS (using OntoCAT) • Currently, this data goes into a report, and is then written back to the database. • But automatic writing back to the Atlas is coming soon! Master headline

13. What ZOOMA does • When running over a submitted text file, ZOOMA can… • Lookup user supplied text values (from a supplied file) and find optimal hits against your ontology of choice • Lookup user supplied text values and recover mappings from the Atlas • Lookup user supplied text values and find possible matches in BioPortal/OLS, again using OntoCAT • Actually, the implementation of the different inputs is the same – we just need to chaange where our text values come from • Again, this generates a report • Error detection doesn’t really mean anything in this case – no mapping errors to detect! Master headline

14. Some tech… • The idea behind ZOOMA is to isolate the logic from the sources of text values and ontology terms. • To achieve this, ZOOMA has several top level interfaces: • OntologyMapper • OntologyMappingFormulator • OntologyTermRetriever • OntologyMappingHypothesis • OntologyMappingHypothesisFactory • OntologyMappingEvaluator • OntologyMappingCalculator • OntologyMappingOutcome Master headline

15. Some more tech… • The infrastructure described means that to use new databases just means writing new OntologyTermRetriever implementations • An OntologyTermRetriever fetches OntologyTerms that possibly match a text value, with enough information to decide how good the match is (the OntologyMappingContext) • New mapping logic can be added by adding implementations of the other interfaces – so at the moment, there is a “RankingBasedCalculator” that implements OntologyMappingCalculator • Implementations can quickly be wired up with Spring Master headline

16. What’s next? • Very short term: do a production release! Ele has already been using ZOOMA to do Atlas mappings, but it’s been a bit ad hoc so far • I need to add support for writing our new mappings into the Atlas database, instead of the report • I want to add an ArrayExpress2 retriever, so we can determine mappings here • And also add write support, to map terms there too • Possibly create an OWL-driven backend? Master headline

17. Questions? Master headline