Counterbalancing between two lists
I want to present stimuli from two different lists (i. e. list a and list b) as mixed. They will come randomly but i want to add the condition that no more than 3 stimuli come from the same list sequentially. Indeed, participants will be presented 3 stimuli from one list (list a), and the next stimuli will be from other list (list b).
Would you help me to solve this problem, please?