Table 2.

Scoring of Multidimensional Responses

	Description	Scoring	Rationale
Case 1	Following a rule change, participants can sort correctly by using the previous rule if the card matches both the previous and the current rule (Figure 2, top panel)	For these trials, the first incidence of negative feedback following the rule change was considered the start of the new sequence	Participants have no prior indication that the rule has changed
Case 2	Following the first negative feedback that indicates a rule change, participants can sort the card such that it matches on both the previous rule and a new rule (Figure 2, middle panel)	These responses were considered efficient if participants engaged in the optimal strategy for the remainder of the sequence, i.e., continuing to use the new rule if correct and switching to the remaining rule if incorrect	This pattern of responses is consistent with optimal switching behavior
Case 3	Participants can switch to the incorrect rule following the detection of a rule change, but receive correct feedback because the card also matches the new correct rule (Figure 2, bottom panel); this may result in a later error because the participant continues to sort on the new but incorrect rule	These later errors were considered efficient if all subsequent trials in the sequence were correct	This pattern of responses is consistent with optimal switching behavior
Case 4	Participants can receive the first negative feedback following a rule change for a response that matched on both the previous rule and the other incorrect rule	These were interpreted as responses based on the previous rule only, and efficient shifts were scored as usual for switches to either of the remaining rules	This pattern of responses is consistent with optimal switching behavior