Precision and Recall (10 points) Suppose that an IR system contains only 1000 do

Question

Precision and Recall (10 points) Suppose that an IR system contains only 1000 documents. A query is known to generate 27 relevant documents as listed below: {d1, d5, d7, d10, ds8, d151, d200, d211, d250, d300 , d399, d401, d405, d450, I473, d500 , d501, d530. d545, d590, doo0, d735. dro0, d20, ds00, dss, d900} Two different IR systems are used to retrieve ranked documents for this query. Each system only returns the top 10 ranked documents in order of ranking Systems 1 and 2 each retrieves documents one at a time in the following order with all 10 documents eventually returned: System 1: d122. d211, d150, dss, d37, d1, d501, ds00, d201. d5. System 2: dio, dro0, dod250, dsed 600, d59, d L422, d500, d. Answer the following and show your work: • (7 points) Calculate the precision and recall values for each system (for 1 document returned, 2 documents returned, ..., 10 documents returned). Using table formatting to keep your calculation organized is required. • (3 points) Which IR system is better? Justify your answer.

Explanation / Answer

Hi,
Lets first understand the defintion of both parameters
Precision- Number of relevant values out of the returned values
Recall- Number of relevant values retrieved out of total relevant values
Now,
system 1:
Relevant ones among the returned ones are - d211,d88,d1,d501,d800,d5
precision= 6/10=0.6
recall= 6/27=0.22
system 1:
Relevant ones among the returned ones are - d10,d700,d250,d88,d600,d7,d500
precision= 7/10=0.6
recall= 7/27=0.259
Hence Sytem 2 is better as it has higher precision and recall
Thumbs up if this was helpful, otherwise let me know in comments

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