# Jaccard coefficient is used to calculate the similarity among asymmetric binary attributes.

## Contingency table for binary data:

 Object 2 Object 1 1 / True / Positive 0 / False / Negative Sum 1 / True / Positive A B A + B 0 / False / Negative C D C + D Sum A + C B + D

In table 1 we can consider the following facts.

A represents that object 1 is True and object 2 is also True.

B represents that object 1 is True and object 2 is  False.

C represents that object 1 is False and object 2 is  True.

D represents that object 1 is False and object 2 is also False.

 Name Fever Cough Test 1 Test 2 Test 3 Test 4 Asad Negative Yes Negative Positive Negative Negative Bilal Negative Yes Negative Positive Positive Negative Tahir Positive Yes Negative Negative Negative Negative

In table 2, Asad, Bilal and Tahir are objects. Negative values represents False and Positive represents Negative.

## Consider 1 for positive/True  and 0 for negative/False. Similarly, we can calculate the similarity of one object with each other object.