IR system: BIM model

Implementation in Python of BIM, a probabilistic model for IR, able to:

• answer free-form text queries.
• allow relevance feedback.
• allow use of pseudo-relevance feedback.

Evaluation of the effectiveness of the system is performed on a set of test queries by:

• precision/recall for a query.
• mean average precision for a set of queries.
• R-precision of the top R ranked documents for a query.
• mean average R-precision for a set of queries.

Dataset

The dataset used is the Cranfield which is a standard Information Retrieval text collection, consisting of 1400 documents (1.6 MB) from the aerodynamics field, in SGLM format. The collection contains 225 queries with relevance feedback.

Structure

The project is structured as follows:

• data folder contains the dataset in original and preprocessed form.
• utils folder contains the file function.py with the functions used in the project.
• bim.py contains the implementation of the model bim.
• index.pkl is the index built by the model bim in pickle format.
• run_all bash script to run the entire project.
• test_model.ipynb jupyter notebook to test the model.

Run

To import the dataset, preprocessing it and build the index, simply execute the bash script run_all:

bash run_all.sh

Results

To see the performance and usage of the index built, run the juptyer notebook test_model.ipynb:

Python Packages

• NLTK for text processing.
• NumPy for numerical operations.

Warning To run bash script run_all enable downlaod of nltk packages in utils/functions.py file at line 6,7:

nltk.download('stopwords')
nltk.download('punkt')