This page describes the configuration of the Snowball algorithm for its application to the PPLRE Evaluation task.

= Notes

For information on the evaluation of Snowball on the task please See: PPLRE Evaluation - Snowball.
For details of Snowball See: PPLRE Snowball Description.
A good system to compare against because it is a well known information extraction system, and the code is available.
Originally tested against the OrganizationHeadquarterLocation(ORGANIZATION,HEADQUARTER,LOCATION) relation.
Some of the challenges of applying Snowball to the PPLRE Task include:

1. The support of only a Binary Relation.
2. The restriction that relations be expressed within a single sentence. [[See PPLRE Research Topics)
3. The assumption that the relationship is one to one. E.g. headquarter(<Organization>) => single <Location>. In our task a proteins can be localized in more than one region. The algorithm may be extensible to non-unique mappings if the seed examples were complete. If not complete then the algorithm is designed to penalize patterns that identify the missing mappings.

Overview

To apply Snowball to the task the following approach was taken:

These configuration decisions are implemented via the configuration file.

Sample Run

% ssh buster % cd ~homira/scripts % echo "Running PO" % ./runall.sh 1 4 % echo "Running PL" % ./runall.sh 2 4

the snowball.ini for the relation is copied over to ../snowball/conf/snowball.ini
the randomseed.pl script is run with two parameters: 1) the relation type and 2) the number of seed.
Snowball is run by executing the ./snowball/runme.sh script.
some of the input/output files (extractedTuples.xml, seedTuples.xml, processedDocIds.xml, hqPatterns.xml) are copied to the run directoryjj
the ./parsingResults.pl script is run with five parameters: 1) the relation type, 2) the run directory, 3) "../data/test/", 4) the number of seeds, and 5) the run Id.

= History

Homira Mojtabaei has been the systems analyst/programmer on the application of Snowball to PPLRE since September 2006.

= Appendix - Sample File Contents