Data Drift

Input distribution change।

$$P\left. (X) \right.$$

changes।

Example:

আগে app-এর users mostly Dhaka।

এখন nationwide expansion।

Concept Drift

Relationship between input and output change।

$$P\left. \left( Y|X \right) \right.$$

changes।

Example:

আগে Friday evening-এ restaurant delay high ছিল।

নতুন operational system-এর পরে Friday effect disappear করেছে।