Question

Suppose that there are a total of 50 data mining related documents in a library of 200 documents. Suppose that a search engine retrieves 10 documents after a user enters ‘data mining’ as a query, of which 5 are data mining related documents. What are the precision and recall?

Answer 1

Answer:

l don't know l am really very sorry

good morning have a great day

Answer 2

Answer:

Precision=50%

Recall =10%

Explanation:

Precision and recall are the terms used in evaluating search strategies.

1. RECALL is the ratio of the number of relevant records retrieved to the total number of relevant data in the database.
2. PRECISION is the ratio of the number of relevant records retrieved to the total number of irrelevant and relevant records retrieved .                                                                                                                                         Now, according to question :

• Let A = The number of relevant records retrieved,  
• Let B = The number of relevant records not retrieved, and  

• Let C = The number of irrelevant records retrieved.                                In this example A = 5, B = 45 (50-5) and C = 5 (10-5).
• Recall = (A / (A+B)) * 100%  & Precision = (A / (A+C))*100%

∴Recall = (5 / (5 + 45)) * 100% => 5/50 * 100% = 10%

∴Precision = (5 / (5 + 5) * 100% => 5/10 * 100% = 50%

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