One design heuristic that we have discussed in class is User Control and Freedom, which acknowledges that users at times choose system functions by mistake and will need a clearly marked “emergency exit” to leave the unwanted state without having to go through an extended dialogue. Thus, undo and redo features must be supported.

Fame

One real-world artifact that exemplifies this heuristic well is Google’s Gmail undo feature. After sending an e-mail, users may not have wanted to send that message due to a typo or simply feeling regret from sending that message. Thus, as an “emergency exit,” users can undo the action by clicking “Undo.”

Shame

An example that illustrates the violation of user control and freedom is the Android mobile operating system. After deleting some text, Android users cannot retrieve the deleted text back. Thus, there is no undo or redo text feature for Android users, violating the user control and freedom heuristic.

Redesigned

User control and freedom can be added to the Android by implementing a similar method to undo and redo text deletions like Apple’s iOS. Users can shake their phones and a pop-up saying “Undo” or “Cancel” appears in their screen. Users can then press the Undo button to retrieve their latest deleted text. Having this option fulfills this heuristic in which users can leave an unwanted state (in this case, retrieving deleted text).