The balance-scale dilemma: either the subject or the experimenter muddles through

We examined two critiques of rule-assessment methodology: (a) the method does not take into consideration other rules that subjects use to solve problems, and (b) its multiple-choice format misrepresents subjects' cognitive level. In Study 1, high school students completed a paper-and-pencil, multiple-choice balance scale questionnaire. Their performance was assessed with Siegler's original rules and a revised set of rules that included an addition and a qualitative proportionality rule. Results showed that Siegler's Rule 3 was not homogeneous and that distinguishing specific patterns of answers among Rule 3 subjects increased the diagnostic value of the rule-assessment methodology. In Study 2, we compared rule-assessment methodology to the Piagetian clinical model. High school students solved balance-scale problems within each method. Results indicated an overall match between Piagetian levels of Siegler's rules, with the exception of Rule 3, suggesting again the pertinence of specifying alternative rules.