Which of the following is NOT a method of data manipulation?

Data duplication is not considered a method of data manipulation as it primarily involves creating a copy of existing data rather than changing or managing the data itself. In data manipulation, the focus is typically on modifying, organizing, or analyzing data to improve its utility or to ensure its integrity.

Input validation, data deletion, and data filtering are all active processes that change the state or content of the data. Input validation ensures that data entered into a system meets specific criteria, thereby preventing errors or inconsistencies. Data deletion removes specific entries from a dataset, impacting the data's overall structure. Data filtering involves selecting specific data items from a larger dataset based on defined criteria, thereby simplifying analysis or reporting efforts. These activities directly affect the data, making them foundational techniques in the realm of data manipulation.