402 undergraduate students at McMaster University in Hamilton, Canada completed a 13-week
course in critical thinking between January and early April of 2001, meeting in one group for two
50-minute classes a week. At the first meeting the course outline was reviewed and a pre-test
announced, to be administered in the second class; students were told not to do any preparation for
this test. Those students who attended the second class wrote as a pre-test either Form A or Form
B of the California Critical Thinking Skills Test (CCTST). The following 11 weeks were devoted
to lectures about critical thinking, except that two classes were used for in-class term tests and one
class was cancelled. Thus the students had the opportunity to attend 19 lectures of 50 minutes each,
i.e. to receive a total of 15.8 hours of critical thinking instruction. In the 13th week, those students
who attended the second-last class of the course wrote as a post-test either Form A or Form B of the
CCTST. The last class was devoted to a review of the course and an explanation of the format of the
final examination.