40 Algorithms Every Programmer Should Know

Confidence

The confidence is a number that quantifies how strongly we can associate the left side (X) with the right side (Y) by calculating the conditional probability. It calculates the probability that event X will lead toward the event Y, given that event X occurred.

Mathematically, consider the rule X ⇒ Y.

The confidence of this rule is represented as confidence(X ⇒ Y ) and is measured as follows:

Let's look at an example. Consider the following rule:

{helmet, ball} ⇒ {wickets}

The confidence of this rule is calculated by the following formula:

This means that if someone has {helmet, balls} in the basket, then there is 0.5 or 50 percent ...