ImpactofOASISUIMAStandardonApacheUIMAOASIS.ppt

UIMA | IBM Research ? 2006 IBM Corporation – All Rights Reserved U M I A February 19, 2008 Impact on Apache UIMA Well Aligned CAS Data Representation: Apache UIMA already uses XMI Abstract Interfaces: Very similar to the Apache UIMA interfaces Minor Differences Type System Language Apache UIMA supports Ecore import/export, but still uses its own “native” type system language, and there are a few minor mismatches in semantics. Many constraints expressible in Ecore are not enforced. Processing Element Metadata: Apache UIMA has some things not in the proposed standard: Indexes Configuration Parameter Groups SOAP Interfaces: Would need to be implemented as new Apache UIMA service adapters. Apache UIMA is designed to make this relatively easy to do. Major Differences Type System Base Model: significant differences Apache UIMA Annotation Base Model is different from proposed standard Apache UIMA Views are 1-1 with Sofas Behavioral Metadata: Apache UIMA has limited behavioral metadata and it lacks precise semantics (and therefore can’t be automatically converted to the proposed standard format). Type System Base Model Differences Naming differences Apache: uima.tcas.Annotation OASIS: org.oasis-open.uima.TextAnnotation Differences in begin, end offsets? Apache: UTF-16 code units (works well for Java) OASIS: Unicode characters? (better for interoperability across platforms) Differences in what can be a Sofa Apache: Annotation points to an object of type Sofa, which contains the data OASIS: Annotation points to an object of type SofaReference, which then points to another object in the CAS that holds the actual Sofa data OASIS allows separate Regional Reference object. Differences in Views Apache: Every Sofa has exactly one View, and every View must have a Sofa. OASIS: Views are general collections of objects. A View may be linked to a Sofa, but this is not required. More than one View may be linked to the same Sofa. Behavioral Metadata Differences Apache UIMA semanti