Classification of strategies. To assess the effectiveness of each
group's problem-solving efforts, their hypotheses were classified
as useful strategies (dimension checking and hypothesis checking,
in descending order of sophistication) or as ineffectual strategies
(stimulus preference, position alternation, and position
preference, also in descending order of sophistication). Useful
strategies are sequences of hypotheses that, when followed perfectly,
will lead to problem solution. Ineffectual strategies are
sequences of hypotheses that can never lead to problem solution