Teachers can track performance/ideas over time for anonymised individuals. This would help teachers see patterns (e.g. allow segmentation sessions), Quiz scores/leaderboard across a term.

Potentially this could be realised with another question type that then stores an anonymised identifier for each student. For example, students respond to a question and enter birthday/surname: this data is not sent to mentimeter but is hashed locally and only the hash is sent/stored by mentimeter (to retain anonymity and privacy).