Different types of user interaction require different forms of responsiveness. For controls and other objects that simulate real-life objects, instantaneous behavior (under 100 ms) is important. To acknowledge to the user that his or her command has been received and understood, the system should respond within half a second to a second. To maintain a continuous user flow, ensure that users are given meaningful feedback and indications every 2–5 seconds. For processes that will take longer than 10 seconds, provide an "escape hatch" so that users don't feel captive to the process.