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 the basic unit for Test-taker responses. Items may be made up of one or several related interactions. As such, the term Interaction should not be considered interchangeable with the term Item.
There are four categories of Interactions: common, inline, graphic, and custom or PCI. There are currently 17 interactions recognized by the QTI standard.
In TAO, interactions include the mechanisms used to score the interaction itself.
For simple Items, correct answers add to the Test score, unlike incorrect answers. Scoring a composite item using standard response templates (match correct, map response, or map response point) are often a more complicated sum.