24 naive albino rats at 5 months of age were tested in a + maze which permitted an alternation with respect to response (left-right), intramaze stimuli (white-black), or to place (east-west) in combinations permitting assessment of the relative importance of these possible determiners of choice alternation. Importance of response was found to be small, if any; that of place, considerable; that of stimulus greater than place. It was concluded, partly from these data, that the relative importance of each of these variables could be manipulated almost at will. Hull''s "reactive inhibition" concept fits these data as an empirical description, but not as a theoretical construct. Glanzer''s "stimulus satiation" concept and Montgomery''s "exploratory drive" both fit as long as the response plays little role, as it does in these data.