1- We have seen that we can deal with polysemy and other problems associated with the use of terms in information retrieval by thesaurus. We can also deal with the same problems with probabilistic or statistical methods (in particular with vector models). Determine a strength and a weakness of the thesaurus approach compared to statistical methods.

2-There are only two types of pets: cats and dogs. I have only seen two cats in my life and no dogs. By maximum likelihood first, then by Laplace smoothing, say respectively what is the probability that the next domestic animal I encounter is a dog?

3-Based on the material presented in this course, what are the different types of interfaces for finding information? What are their respective advantages and disadvantages? List at least one disadvantage (or limitation) and one advantage for each type of interface