Forces

• The system knows information that the actor may not know.
• Even if the actor knows all the information in the system, they may not know which information will be applicable at any given time.
• For human actors, making choices is easier than remembering commands or internal codes.
• For system actors, receiving current information from the system is easier than them having to maintain duplicate copies of that information.

Therefore: Give the system the responsibility of offering that information before the actor makes the decision.