The Feedback Display object displays different screens based on whether the response to a previous slide was correct or incorrect. This introduces the concept of SlideStates, which are different instances of a Slide that are activated based on the value stored in an attribute. The Feedback Display objects monitor the value of the Accuracy attribute from a previous Slide, determine whether it was correct or incorrect, and then display the corresponding SlideState.
Feedback Display objects are typically used during practice blocks for the subject to monitor his performance. SlideStates can be used in other Slide objects as well, as we will see in the next tutorial.