Investigations offormal problem-solving ave conducted with the expectation
that they will predict or at least help understand informal or everyday pro
blem-solving. For instance, ifa student scores well on a multiple-choice ph
ysics exam, the expectation is that the student will also do well on an eve
ryday physics problem. Traditionally the evaluation of problem-solving skil
ls in educational testing and cognitive psychology has been dominated by fo
rmal, objectively scored tests,for example, multiple-choice tests (Garnham
& Oakhill, 1994; Hambleton & Murphy, 1992). The relationship between formal
and informal processes is questionable, however (Galotti, 1989). Formal te
sts may not elicit the same cognitive processes as informal tasks because t
hey lack the process authenticity of informal tasks (Royer, Cisero, & Carlo
, 1993). To address the lack of process authenticity, problem-solving skill
s can be directly evaluated using tasks that are "ill defined" and therefor
e move likely to elicit the cognitive processes associated with informal, e
veryday tasks. The purpose of the present study was to construct informal,
performance tasks to evaluate both junior and senior high school students'
problem-solving in mathematics. The task for students was to evaluate other
students' solutions to two questions in mathematics. Results indicate that
higher-achieving students generally preferred responses reflecting multipl
e approaches to problem-solving. A smaller number of students were also int
erviewed individually and asked to think aloud as they evaluated the soluti
ons. Results indicate that students found multiple approaches to problem-so
lving desirable, while at the same time exhibiting problem-solving biases.