Selection is the second component of the MLP. The MLP parser
reads in the selection "grammar" (procedures) and medical
co-occurrence patterns as filters on the
parse tree generated by the parsing component.
Selection has one main function and two support operations:
- It passes or rejects a parse based on subtrees, relying
on confirmed cooccurrence patterns (in form of cooccurrence
For example, selection will not reject
the sentence Pt had swelling in the arms and fever:
Thus the sentence is accepted by a series of lists
"validated" from the actual medical documents.
- the noun phrase swelling in the arms is accepted by List
HOST-P-N with the host noun swelling (H-INDIC) modified by the
prepositional phrase in the arms (H-PTPART).
- the conjunction of fever (H-INDIC) with the noun arms (H-PTPART) in
the conjoined noun phrases, arms and fever is
rejected by List CONJ-EQUIV-CLASSES.
- the conjoining of swelling (H-INDIC) with fever (H-INDIC) in
the conjoined noun phrases, swelling in the arms and fever is
confirmed by List CONJ-EQUIV-CLASSES.
- the pattern for subject Patient (H-PT), verb had (VHAVE) and two
objects swelling in the arms and fever (H-INDIC) is confirmed
by List SUBJ-VERB-OBJ.
- It reshapes the sentence "vertically" to maintain the
word order of the original input text. In the above example,
the noun phrase fever is raised to the level of the
noun phrase swelling after the
conjoining of arms and fever is rejected,
i.e. pattern swelling in fever does not exist in this sublanguage.
- See List of Cooccurrence Patterns
validated from medical texts.