The PSAT was developed and constructed based on the creative problem solving (CPS)
model (Osborn 1963), which emphasizes students’ divergent-thinking (or creative) ability
(DTA) and convergent-thinking (or critical) ability (CTA) subscales within the following
four-stage problem-solving processes: fact-finding, problem-finding, idea-finding, and
solution-finding. The open-ended essay-question-type instrument employed by the study
aimed to measure students’ problem-solving ability in Earth science.
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