Fields

David Fisher

Field operators are defined by using the .field operator when suffixed on a term or other operator. Field names should be specified in lower case in queries.

Field Restriction and Evaluation

Name Example Behavior
Restriction dog.title counts only occurrences of dog in title field
dog.title,header counts occurrences of dog in title or header
Evaluation dog.(title) builds belief b(dog) using "title" language model
dog.(title,header) b(dog) estimated using language model from concatenation of all title and header fields
#od1(trevor strohman).person(title) builds a model from all title text for b(#od1(trevor strohman).person) - only counts "trevor strohman" occurrences in person fields

Passage Retrieval

You can also use the fields for retrieval of passages within the corpus.

Name Example Behavior
field retrieval #combine[title]( query ) Return only title fields ranked according to #combine(query) (beliefs are estimated on each title’s language model and may use any belief node)
passage retrieval #combine[passage200:100]( query ) dynamically created passages of length 200 created every 100 words are ranked by #combine(query)
#combine[section]( bootstrap #combine[./title]( methodology )) Rank sections matching bootstrap where the section’s title also matches methodology. Note that you can use .//field for ancestor and .\field for parent.

Related

Wiki: Home
Wiki: The Indri Query Language