Eliminate transitive dependencies on the primary key.
Third Normal Form (3NF) is a crucial stage in database normalization that aims to eliminate another type of data anomaly. A table is in 3NF if it satisfies two conditions: first, it must be in 2NF. Second, every non-key attribute must be non-transitively dependent on the primary key. This means that all non-key attributes must depend only on the primary key and not on other non-key attributes. This issue is called a 'transitive dependency'. For example, consider a `Students` table with columns `student_id` (Primary Key), `student_name`, `major_id`, and `major_name`. Here, `student_name` and `major_id` depend directly on `student_id`. However, `major_name` depends on `major_id`, which in turn depends on `student_id`. This is a transitive dependency: `student_id` -> `major_id` -> `major_name`. This design leads to redundancy because the name of a major (e.g., 'Computer Science') will be repeated for every student in that major. It also leads to update anomalies: if a major's name changes, you have to update it in every student's record. To convert this to 3NF, we would decompose the table into two: a `Students` table with (`student_id`, `student_name`, `major_id`) and a `Majors` table with (`major_id`, `major_name`). Now, every non-key attribute in each table depends only on that table's primary key.