What are the measures to prevent mistakes and slips?
Use design patterns that communicate how they work to users, encourage users to double-check their work (especially before deleting), and warn before mistakes are made.
What is error prevention in UX?
Essentially, it involves alerting a user when they're making an error, with the intention to make it easy for them to do whatever it is they are doing without making a mistake. The main reason this principle of error prevention is important is that we humans are prone to- and will always make mistakes.