Boolean Text Retrieval - Building a Boolean Search Engine

Introduction

In the Boolean model for information retrieval, query terms are combined logically using Boolean operators AND, OR and NOT. Given a Boolean query, the system retrieves every document that makes the query logically true (also called an exact match). Each document is treated as a bag of words and word sequence is not considered. Our goal is to implement the methods AND, OR, NOT and perform some queries on a small corpus of Amazon.com reviews on electronics.

Files in the Repository

• all.txt - Contains the raw reviews. Each line of the file is a review/document in our context. There are total 1248 documents.
• BooleanRetrieval.java - Main program which has the boolean querying implemented.
• DatasetFormatter.java - Helper class which provides preprocessing operations such as parsing, generating the vocabulary map and filtering stopwords based on count.
• docs.txt - Contains the reviews represented in document matrix format.
• README.md
• stopwords - Contains a list of stopwords to be filtered.
• vocab_map.txt - Contains the vocabulary map with each word mapped to a unique integer.

Command to run the code

Compile the program using the command 
> javac BooleanRetrieval.java
Run the program using the command
> java BooleanRetrieval <queryType> <queryString 1> <queryString 2> <path to output file>

The first argument is always the queryType (PLIST, AND, OR, AND-NOT) and the last argument is always the path to the output file.

Sample input and output

java BooleanRetrieval AND mouse scrolling and_result.txt
Should produce 
mouse AND scrolling -> [80, 86, 348, 1029] 
as the contents of and_result.txt