The group choice was B for
both groups. This information constitutes the situation components of the instance.
These attributes will act as the retrieval cues: the model will attempt to remember
whether an identical situation has previously been encountered. The model’s memory
stores as an instance each situation that is encountered at each round of the game and
the associated decision taken by the model in that situation.
For a given situation, the model can have up to two matching instances, one with A
and the other one with B as the model’s next decision. If two instances match the
current situation, the model will only retrieve the most active one. Activation of a memory element in ACT-R is a function of its frequency (how often it was used),recency (how recently it was used), and noise.