The Structure of an OpenNLP NameFinder Model

Named Entity Models

Research labs and product teams intent on building upon openNLP and SOLR (which can consume an openNLP NameFinder model) frequently find it important to generate their own model parser or model builder classes.  openNLP has in-built capabilities for this but in the case of custom parsers the structure of the openNLP NameFinder model must be known.

The NameFinder model is defined by the GISModel class which extends AbstractModel and the definition and interfaces exposed can be found in the openNLP api docs on the Apache site.  The structure as below is composed of an indicator of Model type, a correction constant, model outcomes, and model predicates.  Models for NameFinder can be downloaded free from the openNLP project and are trained against generic corpora.

openNLP NameFinder Model Structure

1. The type identifier, GIS (literal)
2. The model correction constant (int)
3. Model correction constant parameter (double)
4. Outcomes
   1. The number of outcomes (int)
   2. The outcome names (string array, length of which is specified in 4.1. above)
5. Predicates
   1. Outcome patterns
      1. The number of outcome patterns (int)
      2. The outcome pattern values (each stored in a space delimited string)
   2. The predicate labels
      1. The number of predicates (int)
      2. The predicate names (string array, length of which is specified in 5.2.1. above)
   3. Predicate parameters (double values)