Query
formulation:
First step here is to expand the query based on domain knowledge (in our case computer science subjects) stored in the form of ontological structure as a tree. Query words are searched in the tree and their parent; children and siblings words are added in the query. Now what is the significance of adding these words? Answer is that they represent similar (in case of siblings) and relative (in case of parent, child) concepts which would increase our recall while searched against documents.