This is a summary of the Effectiveness of Critical Thinking Instruction in Higher Education: A Systematic Review of Intervention Studies
Authors: Dawit T. Tiruneh, An Verburgh, Jan Elen (KU Leuven)
Published in: Higher Education Studies, Vol. 4, No. 1, 2014
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This study reviews 33 empirical studies on teaching critical thinking in college classrooms. The researchers searched three databases and found 88 candidate articles. They narrowed that list to 33 studies that met strict criteria: each had to include a real instructional intervention, a control or pretest-posttest comparison, and a measure of critical thinking skills or dispositions.
Four teaching approaches
The researchers sorted the studies into four categories:
- General: critical thinking taught as its own separate course
- Infusion: critical thinking taught explicitly inside a regular course
- Immersion: critical thinking embedded in a course without naming the skills directly
- Mixed: a combination of a standalone course plus embedded instruction
Sixteen of the 33 studies used immersion, the largest group. Nine used infusion. Only five used the general approach, and three used the mixed approach.
General and mixed approaches produced the strongest results. Four of five general-approach studies showed significant gains, and two of three mixed-approach studies did too. Infusion studies succeeded about half the time. Immersion studies succeeded the least often, with only half showing significant gains.
The authors caution against over-reading these numbers. General and mixed approaches appeared in far fewer studies, so the sample size is small. Still, the pattern suggests that naming critical thinking skills explicitly, rather than hoping students absorb them by osmosis, tends to work better.
Direct instruction beats implicit methods
The review also compared teaching strategies. Direct instruction, where a teacher explains thinking principles up front and then guides students through practice, discussion, and feedback, consistently produced better results than implicit strategies.
Implicit strategies included lecture-versus-discussion formats, concept mapping, and higher-order questioning without explicit skill instruction. Results for these were mixed. Problem-based learning was the one implicit strategy that showed consistent gains across three studies. Higher-order questioning showed almost no significant gains on general critical thinking measures, though it did improve performance on subject-specific tests.
The authors point to a design problem behind these inconsistent results. Many implicit-strategy studies never specified which critical thinking skills they targeted, what kind of feedback students received, or what roles students played in group work. Without those details, it is hard to know why an intervention worked or failed.
Student and teacher characteristics
The review looked for patterns tied to student traits like gender, year in school, and prior academic performance. The data here was thin. Not one of the 33 studies reported critical thinking outcomes separately by gender, despite prior research suggesting gender differences exist.
Year level showed a mild pattern. First-year students benefited more from general or infusion approaches. Second-year students responded better to immersion. Five studies matched GPA between experimental and control groups before the intervention, and all five reported significant gains, suggesting that mismatched prior knowledge between groups can mask an intervention’s real effect.
Teacher experience mattered too. When a study’s own researchers delivered the instruction, 60% of those studies showed gains. When regular classroom teachers delivered it, only 41% did. For infusion and immersion approaches specifically, gains appeared mostly when a trained teacher or the researcher led instruction, suggesting these embedded approaches demand more skill to execute well.
How you measure critical thinking changes the outcome
The type of test used to measure critical thinking swayed the results. Studies using researcher-made, non-standardized tests reported gains 93% of the time. Studies using standardized tests, like the Cornell Critical Thinking Test or the Watson-Glaser Critical Thinking Appraisal, reported gains only 55% of the time.
Item format mattered within standardized tests too. Essay-style questions produced stronger results than multiple-choice questions. Five studies used both a general test and a subject-specific test side by side. All five showed gains on the subject-specific test, but only one showed gains on the general test. This points to a transfer problem: students often improve at applying critical thinking within the course material but struggle to apply the same skills to unfamiliar topics.
Bottom line
The review found real evidence that critical thinking instruction can work, but it found no strong case for one instructional approach over another. What mattered more was how the instruction was designed and delivered. Explicit teaching of thinking skills, done by someone trained to teach them, produced more consistent gains than implicit approaches.
The authors close with a call for better-designed studies. Most of the 33 studies skipped basic details: what specific skills were targeted, what tasks students worked on, what feedback they got. Without that information, researchers cannot build a reliable case for any single teaching method. The authors recommend that future studies report student characteristics like gender and GPA consistently, and pay closer attention to how they measure critical thinking in the first place.