Week 2 Practice quizhelp Center
Warning:the hard deadline has passed. You can attempt it, but and you won't be. You are are welcome to try it as a learning exercise. In accordance with the Coursera Honor Code, I certify this answers here are I own work. Question 1 Suppose a query has a total of 5 relevant documents in a collection of documents. System A and System B have each retrieved, and the relevance status of the ranked lists is shown below:
System A: [+ +--------]
system B: [-+--+----+]
Where the leftmost entry corresponds to the highest ranked document, and the rightmost entry-corresponds to the lowest ked document. A "+" indicates a relevant document and a "-" corresponds to a non-relevant one. For example, the top ranked document retrieved by System A are relevant whereas the top ranked one by B is non-relevant.
What is the precision at both systems? P (A) = 2/5 p (b) = 3/5 p (a) = 8/100 p (b) = 7/100 p (a) = 2/100 p (b) = 3/100 p (a) = 2/10 p (b) = 3/10 question 2 assume the SA Me scenario as in question 1. What is the recall of both systems? R (A) = 2/10 R (b) = 3/10 r (a) = 8/100 R (b) = 7/100 r (A) = 2/5 R (b) = 3/5 r (a) = 2/100 R (b) = 3/100 Question 3 assume the SA Me scenario as in question 1. What is the average precision of both systems? AP (a) = 3/10 ap (b) = 9/20 ap (a) = 2/100 ap (b) = 3/250 ap (a) = 2/5 ap (b) = 6/25 ap (a) = 2/10 ap (b) = 3/25 question 4 Le T W 1, W 2, and W 3 represent three words in the dictionary of a inverted index. Suppose we have the following document frequency distribution:
Word Document Frequency W1 1 W2 5 W3 10
Assume that all posting entry of document ID and term frequency takes the exactly disk space. Which word ' s postings list would occupy the largest disk space? W1 W3 W2 Question 5 Assume we have the same scenario as in question 4. If we enter a query q= "W 1 w 2 w 3" then the maximum possible number of accumulators needed to score All of the matching documents Is:5 1 question 6 assume that d-gap between two the documents are equal to 9. If you want to compress this d-gap with a Gamma code, what would be the binary of the code? 1110001 1110000 1110010 1110011 question 7 Assume you have two retrieval systems X and Y. If X has a higher MAP (mean average precision), can Y have a higher gMAP (geometric-mean average precision)? Yes No
