What is an Interaction?
"Interactions allow the candidate to interact with the item. Through an interaction, the candidate selects or constructs a response. The candidate's responses are stored in the response variables. Each interaction is associated with (at least) one response variable." - Question and Test Interoperability standard, published by IMS Global.
Interactions serve as a basic unit of Test-taker response. Items may be made up of one interaction, or several related interactions. As such, the term Interaction should not be considered interchangeable with the term Item.
There are four categories of Interactions: simple, text-based, graphic, and miscellaneous. There are more than 17 interactions recognized by the QTI standard.
In TAO, interactions include the mechanisms used to score themselves.
For simple Items, correct answers add, unlike incorrect answers, to the Test score. Scoring a composite item using standard response templates (match correct, map response, or map response point) is often a more complicated sum.