Information Retrieval &
Web Search Engines
Lecture 3
Please note: The exercises will be neither collected, nor corrected, or graded.
Even though the homework assignments are optional, you are encouraged to answer them and to discuss them in small groups, as they will help you prepare for your final exam.
Given is the following subset of documents from a document collection:
π·1 = {π‘1, π‘5, π‘9} π·4 = {π‘4, π‘5, π‘10} π·2 = {π‘1, π‘2, π‘4, π‘5, π‘9} π·5 = {π‘3, π‘5, π‘6, π‘7} π·3 = {π‘3, π‘6, π‘7, π‘8} π·6 = {π‘1, π‘2, π‘10} and the following queries:
π1 = (π‘1 ππ π‘5) ππ’π‘ πππ‘ (π‘3 ππ π‘2) π2 = (π‘1 πππ π‘5) ππ (π‘3 πππ π‘2)
1. (Fuzzy Logic Model)
Given the following fuzzy weights for π·1 = {π‘1/0.4, π‘2/0.8, π‘3/0.8, π‘5/0.2, π‘8/0.9, π‘9/0.6, } a. Compute the relevance of document π·1 to both queries π1 and π2
b. What is the motivation behind using fuzzy weights?
c. Assuming the following journal collection: π·1, π·4 and π·6 = {π‘5, π‘9} constitute an entire document collection, compute the fuzzy membership degree for the collectionβs terms with respect to π·1.
2. (Coordination Level Matching)
a. Given the following query: π = {π‘1, π‘2, π‘4} on the document collection defined in 1.c re- turn level-based matching of these documents for π.
