Critical Thinking and Assessment

Critical Thinking and Assessment

As faculty seek to make CTS the gold standard and the aim of dental education, it is important to assess their investment of time and effort. It is also important to consider what the purpose of assessment will be.  The purposes of assessment can range from diagnosis to research and accountability. For example, asking students to take critical thinking skills test inventories allows researchers to diagnose students’ critical thinking skills. 65 This information could be used to make decisions about where to focus instruction. Also, test scores could be shared with students so that they become aware of their CT strengths and weaknesses. 65  The scores that result from an administration of a critical thinking skills inventory midway through students’ program or at the end can be used to inform teachers about the effectiveness of their efforts to teach student CTS. 65  When critical thinking scores become available researchers can explore how instructional practices or the design of the curriculum influenced outcomes. For example, qualitative inquiry could be used to examine the amount of time used (i.e., by documenting the frequency of critical thinking strategies) to develop students’ CTS in didactic and/or clinical learning environments and compared to empirical changes in students’ CTS. Qualitative inquiry could also be used to interview faculty and students about the quantity or quality of instruction that is aimed at developing students CTS. Providing information about students’ CTS might also result in holding dental schools accountable for the students’ critical thinking skills prowess. 65

Currently some dental schools, for example, are participating in a study that will correlate third and fourth dental students’ critical thinking skills using the CCTST with their GPA, and National Board Scores for Part I and Part II. As more dental schools across the US and Canada participate in studies like this one, information about the usefulness of the CCTST measure may become better known. However, it is important to recognize that the NBDE will soon become pass/fail.

In a study about the predictive validity of the CCDTI and CCTST on dental hygiene students’ performance on the National Board Dental Hygiene Exam (NBDHE), William et al. reported that CCTST explained a statistically significant (p <. 05) amount of the variance (exceeding GPA, number of college hours and student’s age) in students’ (n = 76) multiple-choice and case-based NBDHE scores.66 The CCDTI scores were not a significant predictor of either outcome.

The CCTST and HRST are measures of general CTS, are not domain specific to dental skills. Other researchers may chose to develop a measure of critical thinking that specifically measures dental skills.  Such an endeavor is likely to take several years, although it may be worth the effort. More studies are needed in dental schools to explore how instruction leads to changes in students’ dental critical thinking and whether variables like GPA, demographics, or board scores predict pre-test, post-test changes in mean scores.

Dental school might also consider qualitative studies of instruction in conjunction with using the CCTDI and CCTST; the HRST, the CCTDI, and CCTST; and the PJRF, or the HRST and CCTST.  It is important to point out that the use of pre-test and post-test comparisons are also fraught with problems. For example, if a control group is not used, then the findings are dubious.65Also, as Ennis points out: “The use of the same test for pretest and posttest may alert students to the test questions.” 65

Faculty Critical Thinking Skills

It cannot be assumed that all dental faculty have global thinking skills themselves. Thus, it is also important to assess faculty’s critical thinking skills abilities and offer professional development opportunities so that faculty can develop expertise in learning how to teach students critical thinking skills.9 Dental school administrators must make a commitment to assessing and studying faculty’s global critical thinking skills and providing opportunities for faculty to expand their teaching repertoire. These practices should apply to current faculty as well as newly recruited faculty. The quality of teaching can only be as good as the instructional repertoire of the faculty. Further, the goal of teaching students to use critical thinking skills is to raise the average level of student instruction and ultimately patient care.

Avenues for research

While experts continue to debate whether CT is a learned skill or is developmentally hard-wired, perhaps dental educators should consider testing the notion of whether dental curriculum helps students without CT dispositions become more proficient in their critical thinking skills abilities. The following experiment is suggested. Have all incoming dental students take the CCDTI and the CCTST or the HSRT during the first weeks of school. Using a double blind matched pair samples of students with and without CT could be evaluated periodically (perhaps twice yearly in years 1 and 2 and twice a year in years 3 and 4) to determine if their ability to reason has improved. An expert panel could be used to rate students on their reasoning skills when they are given practice-based problems that are commensurate with their year of training. Then the mean changes between the two groups could be compared from year to year. Conducting an experiment of this sort would also address the lack of research on students’ development of CTS and concerns about a lack of valid assessment instruments to assess changes in CTS. Inter-rater reliability would need to be established among the expert panel prior to the experiment. Before the end of the 4th year, students with and without CTS could take CCDTI and CCTST or HSRT tests again. Mean changes between the initial and final tests could be compared to determine if there are significant changes as well as to the expert panel ratings. Dental educators should design and conduct their own studies.


65 Ennis RH. Teaching for higher order thinking. Theory into Practice 1993; 32 (3): 181

66 Williams KB, Schmidt C, Tilliss TSI, Wilkins K, Glasnapp DR. Predictive validity of critical thinking skills and disposition for the national board dental hygiene examination: a preliminary investigation. J Dent Educ 2006: 70(5): 536-544.