EXERCISE 1  Issue a query of your choosing to any Web search engine that will retrieve 10 or more hits. Using the order of retrieval as an index, go to odd retrieval documents (i.e., hits 1, 3, 5, etc.) and assign to each a score in the range [–10,+10] indicating how relevant you found it. Now repeat the exercise for the even documents. Finally, analyze your assessments for each of the triplets of documents: 1,4,7; 2,5,8; and 3,6,9. How well do they satisfy the required properties of a metric (cf. Section 5.2.2)?

EXERCISE 2  Compute the ESL of a random retrieval using each of the following two predicates:

1. N relevant documents; and
2. P percent of relevant documents.

Discuss the effect of the measures relative to query generality.