Date of Award


Document Type


Degree Name

Doctor of Education (Ded)


Educational and School Psychology

First Advisor

Mary Ann Rafoth, Ph.D.

Second Advisor

William Barker, Ph.D.

Third Advisor

Edward Levinson, Ed. D.

Fourth Advisor

Dr. Betty J. Finney

Fifth Advisor

Betty J. Finney, Ph.D.


This experimental study examined the effect of direct instruction in critical thinking on the critical thinking ability and academic achievement of Freshman students being tutored in repeat courses at a rural southeastern Pennsylvania university. This study used the Thinker's Guides, based on Richard Paul's model of critical thinking, and the Rationale Argument Mapping Program, based on the research of Tim van Gelder. Subjects' abstract reasoning and problem solving skills were measured by the Category Test: Computer Version – Research Edition (CAT:CV). Subjects’ critical thinking skills were measured pre- and post- instruction using the California Critical Thinking Skills Test – Form 2000 (CCTST – 2000). Data were analyzed to determine the ability of the CAT:CV and the CCTST – 2000 Post-test Total Ranked Score to predict subjects' improvement in critical thinking skills and academic achievement following instruction. Data were also analyzed to determine the effect of direct instruction using the Thinkers Guides or Rationale on the improvement of subjects' critical thinking skills (CCTST-2000 total and subscale scores) and final grades. Data analysis using MANCOVA revealed no significant relationship between the intervention method and subjects' post-test critical thinking skills. However, the Thinker’s Guides Group and the Control Group demonstrated improvement in academic achievement. Multiple Linear Regression revealed that the CAT:CV and the CCTST – 2000 predicted subjects' final grades, but a more significant contribution to final grades was from the CAT:CV. MANOVA results revealed no significant findings regarding the effect of intervention group on subjects' CCTST – 2000 subscale scores. Finally, data were analyzed to determine the relationship between sex and the improvement of critical thinking and academic achievement. Sex was not a significant factor for this study. Students repeating courses demonstrated improved academic achievement based on final grade, but the effect cannot be attributed to intervention method alone. These findings suggest that further research is needed using a larger sample size to determine the extent to which direct instruction using the Thinker's Guides and the Rationale Argument Mapping Program as a supplement to tutoring can improve students' critical thinking ability and academic achievement.