In a set of two experiments we will attempt to verify the empirical predictions made by the CASES model. Both experiments are based on a series of trials. During each trial the subject is shown a stimulus "Fennimal". Each Fennimals consists of two features: type (the shape of the Fennimal) and a color-location feature. The contents of these features is pseudo-randomly selected per subject (for details regarding the structure of this random selection, see "Conditions"). Following the presentation of the Fennimal the subject is then shown between 1 and 4 toys, which can be given to the Fennimal by dragging it to the creature. In some trials this action is then followed by feedback.
Both experiments follow an identical structure. At the start of each experiment subjects will be given 5 training blocks. Each training block consists of the same 4 trials (in random order). During each training trial the subject can only select a single object to hand to the Fennimal. This actions is always followed by a positive feedback indicating that this Fennimal liked the given object. All trials in these blocks are un-incentivized.
Subjects are then given a quiz, included to ensure that subjects have succesfully memorized all training-block Fennimals. In this quiz subjects again see the same 4 Fennimals as before and have to match them to the correct action (i.e. hand them the correct object). If subjects make any errors during this quiz then they will be presented with an additional training block and will have to re-take the quiz (this process is repeated until the subject passes the quiz). If the subject does not make any errors on this quiz, then he/she will continue to the second phase of the experiment. During this phase the subject will complete 8 more trials, divided in two blocks of 4 trials. During each of these trials the subject can earn a Token for selecting the "correct" action (i.e. the action predicted by the CASES model). If the subject selected the CASES-predicted action on all 8 trials then he/she earns an additional bonus of 4 Tokens. No feedback regarding the subject's performance is provided during this block; the subject will only learn of their earnings at the end of the experiment.
During the first blockof the second phase of the experiment the subject will encounter 4 new Fennimals. These 4 new Fennimals form the TEST trials. Depending on the structure of the experiment, these Fennimals will share some features with a Fennimal encountered during the training blocks. Subjects are now given a selection of items to hand to the Fennimal (the exact number of which depends on the experiment). If the subject selects the action predicted by the CASES model, then they earn a Token (feedback on their earnings is only provided at the end of the experiment).
After the TEST block there is one additional TEST-TRAIN block, in which subjects encounter the original 4 Fennimals (encountered during the training blocks) and can select which of the four items to hand to the Fennimal. This block functions as a check on whether subjects succesfully stored the original Fennimals as episodic memories. If the subject selects the correct action, then he/she earns an additional Token.
After completing all 8 trials of the second phase, the subject automatically continues to the a short questionnaire. After this questionnaire the experiment is concluded.