HW#4 --- last modified February 06 2019 04:16:13..

Solution set.

Due date: Apr 25

Files to be submitted:
  Hw4.zip

Purpose: To gain experience with different index compression algorithms.

Related Course Outcomes:

The main course outcomes covered by this assignment are:

LO4 -- Give an example of how a posting list might be compressed using difference lists and gamma codes or Rice codes.

CLO6 -- Be able to evaluate search results by hand and using TREC eval software.

Specification:

This homework consists of two parts a written part and a coding part. For the written part do the following exercises out of Buttcher, Clarke and Cormack: 6.1, 6.4, 6.5, and 6.10.

For the last part of the homework I want you to download and compile the trec_eval program from NIST. I want you to create a text_qrels_file.txt by hand based for your corpus and topics of Hw2 (not Hw3). Then I want you to repeat the experiments you did for homework 2 to compare stemming versus chargramming, but this time have your code output in the format of a trec_top_file and use trec_eval to compute all the statistics. Your zip file should contain all the text files you generated for your experiments and it should contain Experiments.txt which explains what you did and summarizes the results you got. It should also contain actual trec_eval output.

Point Breakdown