# Distance measure for symmetric binary variables

Last modified on May 26th, 2018 at 1:49 pm

**How to calculate proximity measure for ****symmetric ****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 |

Name | Gender | Job_Status |

Akram | Male | Regular |

Ali | Male | Contract |

**Consider 1 for positive/True and 0 for negative/False**

Here we are considering Male and regular as positive and female and contract as negative.

**A = **Akram is positive and Ali is also positive. so A=1 because Ali and Akram both are male and the male is positive.

**B =** Akram is positive and Ali is negative. So B=1 because Akram is regular that is positive and Ali is on contract that is negative

**C =** Akram is negative and Ali is 1. So C = 0 because Akram is never negative. He is male and regular. and male and regular both are positive.

**D =** Akram is negative and Ali is also negative. So D=0 because Akram is never negative. He is always positive(male and regular).