## Jet Tools: Annotators and Resources

The analysis of a document in Jet is performed by a set of tools. Most of these tools are annotators: each annotator adds a set of annotations to the document. Many of these annotators use linguistic resources to perform their task; for example, the parser uses a grammar; the pattern matcher uses a pattern set. These resources are described along with the annotators which use them. The annotators currently implemented in Jet are

tool | function | linguistic resource
Tokenizer | divides a text into tokens |
Sentence Splitter | divides a text into sentences |
Lexicon Lookup | looks up definitions of words in a dictionary | lexicon
Part-of-speech Tagger | assigns parts of speech to words in context | HMM of part-of-speech sequences
Name Tagger | tags names, dates, times, ... | HMM of names
Noun group Chunker | tags noun groups | Maxent model of noun groups
Parser or Statistical Parser | determines syntactic structure | grammar
Pattern Matcher | identifies structure through regular expression pattern matching | pattern set and concept hierarchy
Reference Resolver | resolves anaphoric references |
Scorer | scores performance against standard |