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Milieu in Dental School and Practice |
Key words: structured interview, DAT, personality measures, predicting performance
Submitted for publication 12/18/06; accepted 02/28/07
| Abstract |
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Smithers et al.2 showed that a typical admissions interview was in fact worse than neutral in that it was negatively associated with students performance in the first year of dental training, did not predict academic performance, and may have led to poor selection decisions. For example, applicants who had high scores on the interview performed at lower levels in their first-year studies. Combining the interview data with DAT score and grade point average leads to admission of a higher proportion of students who are not likely to do well in their initial coursework. The proportion would depend on the weight assigned to the interview. This is one reason why the Canadian Dental Association (CDA) commissioned a new, structured interview based on state-of-the-art contemporary interview techniques. The main purpose of this article is to report the reliability and validity of the new CDA structured interview based on longitudinal data from four dental schools collected over a four-year period. In addition, Smithers et al.,2 as well as Chamberlain et al.,3 have demonstrated the benefits of adding a measure of personality to admission programs. As a secondary purpose, our study reports additional longitudinal data on the use of personality measures in the selection process.
| Interviews and Dental Student Selection |
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Starting in the mid-1980s, industrial/organizational psychologists have improved both the reliability and validity of interviews by introducing a high degree of structure into the interview, developing answer keys used to assess the candidates answers, providing training to the interviewers on how to administer and score the interview, and most importantly, having the questions on the interview assess characteristics or competencies that are directly related to the job or occupation for which the candidate is being interviewed. Structured interviews that follow these procedures tend to have a validity, corrected for range restriction and unreliability, of .51, while the typical unstructured interview has a validity coefficient ranging from .14 to .19.7
There are two common types of structured interviews. The situational interview (SI)8 asks candidates what they would do in a hypothetical situation, while the patterned behavior description interview (PBDI)9 asks candidates about past behavior with the assumption that past behavior is the best predictor of future behavior.9 SI questions are future-oriented, whereas PBDI questions are past-oriented. Both types of interviews have acceptable interrater reliabilities when descriptively anchored rating scales are used to rate responses. SI and PBDI are relatively equal in their ability to predict performance.10,11 Conway and Peneno12 suggested that structured interviews should include a mixture of SI and PBDI questions. Table 1![]()
presents an example of each type of interview question designed to assess the same competency.
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| Development of a New Canadian Dental Association Interview |
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Starting in 1998, the CDA commissioned a study to formally identify the factors that were related to success in dentistry. Using job analysis techniques, a study conducted by Tomini and Keown identified eight competencies: communication, conscientiousness, integrity, judgment and analysis, self-control, sensitivity to others, tact and diplomacy, and continuous learning.13 Subsequent research replicated the work of Tomini and Keown using many focus groups comprised of dentists, dental students, and dental patients. The focus groups produced critical incidents that described successful or unsuccessful behaviors for the first seven competencies. The eighth competency, continuous learning, was deemed relevant to practitioners but not to student applicants. Each critical incident was rated with a seven-point scale ranging from "Highly Ineffective" to "Highly Effective." Ten graduate students in industrial/organizational psychology then assigned each critical incident to one of the seven competencies. Only when seven of the ten students agreed on the assignment was a critical incident retained for further development into a question. More than 500 critical incidents were retained and then formed the basis for the structured interview questions. Each critical incident was edited into both a PBDI and an SI question of the type illustrated in Table 1![]()
. The behaviors listed in the critical incident were used by the graduate students to generate the initial answer keys for each question, again requiring 70 percent agreement on whether the proposed response constituted a "good," "marginal," or "poor" answer.
All of the questions and answer keys were then reviewed twice by the CDAs Dental Aptitude Test (DAT) Committee with the result of modifying almost all questions and keys with some questions rejected as unsuitable. The DAT Committee members were admissions officers from dental schools, all with considerable experience in the practical application of interviews for selection to dental school. The committee was guided by one of the authors who had expertise in the development of structured interviews. The main concern of the DAT Committee was to ensure that the questions were not dependent on a previous knowledge of dentistry and that they were generic in scope.
Participating dental schools first used the new interview in the cycle for admission to dental school in September 2001. Each school selected a pool of interviewers who underwent on-site training in the use of the new interview. The interviewers also had access to a new handbook designed for their use that explained the new interview structure and process. The training, which was conducted by dentists experienced with the interview, included simulated interviews and practice in scoring the seven competencies. The training session is now provided each year at each participating school and is mandatory for anyone volunteering to serve as an interviewer.
All interviews are conducted by a panel of two trained interviewers, usually faculty members and dental practitioners, although some schools use a senior dental student as one of the interviewers. Each school is sent a pool of fourteen questions, one SI and one PBDI question for each of the seven competencies, prior to the start of their admissions process. Each interview panel is free to choose either of the two questions designated for each competency. As well, each dental school receives a slightly different pool of questions. This variability in the interview protocol was introduced to reduce the chance of subsequent candidates knowing the exact questions being asked during the interview, either from prior candidates who had completed the interview or from being interviewed at different dental schools.
Each question is scored on a five-point scale with behavioral anchors as indicated in Table 1![]()
. The score from each interviewer is combined into a composite, and only their total score70 being the maximum possible score (35 from each interviewer)is used as part of the admissions process. Initial research demonstrated that the new interview had an acceptable interrater reliability of .80.14
To date, Canadian dental schools have used the new interview in five admissions cycles with 1,467 applicants. The reliability remained consistent from our early research over these interviews at .81. Although the new interview met professional standards for construct validity, its ability to predict dental students academic and/or clinical performance remained to be determined. Thus, the major objective of our research was to assess the validity of the new CDA interview with respect to both academic and clinical criteria.
| Other Predictors of Dental School Success |
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Conscientiousness is comprised of traits such as organization, persistence, and purposefulness.26 Dental work is often repetitive in nature, involving the need for determination, deliberation, caution, and reliability27traits similar to those associated with Conscientiousness. Surprisingly, Smithers et al.2 did not find a relationship between Conscientiousness and dental school performance, but Chamberlain et al.3 did show that Conscientiousness predicted various dental school performance criteria. Specifically, Chamberlain et al. found that conscientiousness was correlated .23 with Year 1 performance and .47 with Year 3 academic performance. Evans and Dirks28 also found that Conscientiousness was a significant predictor of at least one laboratory course grade of dental technology students (r=.32).
Agreeableness is associated with traits such as sincerity, compassion, honesty, and forgiveness.26 Evans and Dirks28 reported that Agreeableness was positively associated with at least one laboratory grade (r=.23); Chamberlain et al.3 found a significant positive correlation (r=.30) with first-year academic performance. Smithers et al.,2 however, did not find any relationships among Agreeableness and performance criteria.
Openness to Experience is characterized by the active seeking and appreciation of new experiences and has been associated with general knowledge29 and creativity.30 It reflects a preference for developing new solutions to problems through creativity. The dental setting is rather controlled and may not provide much opportunity for creativity or intellectual curiosity; thus, Openness to Experience may not be related to success in dental school. In fact, Evans and Dirks,28 Smithers et al.,2 and Chamberlain et al.3 did not find positive relationships between the broad Openness factor and any of their criteria.
Extraversion is characterized by an increased quantity and intensity of interpersonal interaction.26 In dental school, Extraversion might be important for predicting performance in clinical coursework where there is increased patient interaction. Similar to the results for Openness, all three recent studies2,3,28 failed to find a relationship between the broad factor of Extraversion and their criterion measures.
Neuroticism is associated with a tendency to experience negative affect, such as anxiety, depression, and hostility, and its absence is often referred to as Emotional Stability. In other words, Emotional Stability reflects a calm, relaxed approach to situations, events, or people.26 Thus, high Neuroticism may impair academic performance. Evans and Dirks28 and Smithers et al.2 did not find any relationships between Neuroticism and performance criteria. Chamberlain et al.,3 however, did find that Neuroticism was negatively related to a new measure of student professional behavior in the clinic (r=.27). Essentially, students who were more emotionally stable were perceived as exhibiting a higher degree of professionalism.
Overall, there is a mixed view of the relationship between personality and dental students performance. Differences across studies might be due to the use of different samples, which have been generally small, and/or different criteria. Nonetheless, the contradictory results highlight the need for additional research. Thus, a secondary objective of our study was to continue to examine the validity of broad factors in predicting both academic and clinical performance in dental school.
The Dental Aptitude Test
Extensive research has established the validity of the Dental Aptitude Test (DAT), a measure of cognitive ability, as a predictor of dental school performance and has generally found that the DAT is a significant predictor of didactic or preclinical coursework.2,3,3136 Although the DAT is associated with didactic performance, it has not predicted success in clinical coursework in which students engage in clinical treatment interactions with patients and behavioral skills such as verbal communication and empathy might become more critical to performance.2,3,24,32,34,35 Based on past research, the DAT should predict performance in the first and second years of dental training in a traditional curriculum.
| Methods |
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This study was reviewed and approved by the four Research Ethics Boards (REB) of the participating dental schools as well as the REB for Saint Marys University, following the policy on research with human participants developed by the three Canadian federal granting agencies. All students were assured that any information obtained through the course of the study would remain confidential and that only aggregate data would be reported. Students were further assured that participation or nonparticipation in the study would have no impact on their grades and that course instructors would not have access to any of the information they provided. Students signed informed consent forms as part of their participation in the study.
The measures used were as follows.
Dental Aptitude Test (DAT).
Scores from the Reading Comprehension Examination, Perceptual Motor Ability Test, and Academic Average components of the DAT were obtained from the student participants official records. We used these three DAT components as previous research indicated that these were the best measures of cognitive ability.2,3 We did not use undergraduate GPA as a control variable because this was correlated with the DAT Academic Average. The DAT Academic Average was a better indicator since it is based on a standardized measure taken across all applicants.
The CDA Interview.
Each CDA interview, as described above, consisted of seven questions, one for each of seven competencies, with each rated on a five-point scale yielding 35 as the highest possible total score. Pairs of dentists, or in some cases a dentist and senior dental student, conducted each interview, and pairings were not consistent throughout the interview process. Scores were summed to create a total interview score for each student with 70 being the maximum possible score. As part of validating the new interview, dental schools that used the interview as part of their admissions process had agreed to submit data from the interview to the Canadian Dental Association. At present, seven schools have forwarded data from 1,467 interviews. The reliability for the interview, based on interrater correlations between the first and second interviewer for the data set, is r=.81 (p<.001). The reliability for the interview data used in this study, based on 355 participants, was lower, r=.67 (p<.05), but still at an acceptable level of reliability.
Personality.
Costa and McCraes26 NEO-PI-R, Form S was used to assess the Five Factor Model of personality. The inventory consists of 240 items rated on a five-point scale ranging from 1 (strongly disagree) to 5 (strongly agree). The reliabilities of the five factors, as measured by Cronbachs Alpha coefficients, were excellent: Neuroticism=.92; Extraversion=.87; Openness=.88; Agreeableness=.90; and Conscientiousness=.88.
Criterion Measures.
A weighted GPA was calculated for all courses in the first year of dental training (e.g., basic health sciences courses and pre-clinical dentistry courses). The GPA was a composite of the grade in each course weighted by the value of the course divided by the total number of credit units for that year. All of the subsequent GPAs were calculated in this way for each school.
A weighted GPA was computed for all courses designated as clinical in the second, third, and fourth years of dental training. Courses were designated by faculty at the participating school as clinical if more than 50 percent of the final grade came from direct clinical activities (i.e., patient treatment). A weighted GPA was also computed for all courses designated as didactic in the second, third, and fourth years of dental training. That is, if more than 50 percent of the final grade came from nonclinical activities (i.e., lecture, seminar, or presentations), the course was defined as didactic by faculty at each institution. Chamberlain et al.3 presents examples of specific courses categorized as either "clinical" or "didactic."
| Results |
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, for the DAT and Interview are presented in parentheses along with the uncorrected coefficients, r.
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=.46, r=.35, p<.001), Year 2 academic performance (
=.52, r=.40, p<.001), and Year 2 clinical performance (
=.23, r=.34, p<.01). The Perceptual Ability component correlated with Year 1 performance (
=.21, r=.18; p<.05) and Year 2 clinical performance (
=.27, r=.21, p<.05). Reading Comprehension scores correlated with only Year 1 performance (
=.25, r=.21, p<.05). None of the DAT components predicted either academic or clinical performance in Year 3 or Year 4
As can be seen in Table 3
, none of the three DAT components correlated with scores on the Interview; they are assessing different aspects of the applicants behavior. The DAT components, except for two instances, were not associated with the personality factors. The DAT Academic Average had a low level of association with Openness to Experience (
=.19, r=.15, p<.05). This personality factor is often associated with willingness to learn; in this case, students with higher levels of Openness were more likely to have higher DAT Academic Average scores. As well, the DAT Perceptual Ability Test was negatively correlated with Extroversion (
=.16, r=.15, p<.05). Students who were more outward-going tended to perform less well on the Perceptual Ability Test than students who were more inward-looking.
The CDA Interview
Scores on the interview were significantly correlated with both Year 3 clinical performance (
=.31, r=.18, p<.05) and Year 4 clinical performance (
=.45, r=.25, p<.001) That is, students who received more favorable scores on the interview performed better in third- and fourth-year clinical coursework than students who were rated lower on the interview. The interview did not predict academic performance in the final two years nor for any aspect of performance in the first two years. In this sense, the interview and the DAT measures are complementary, in that they are assessing different aspects of the applicants behavior: the DAT is predicting Years 1 and 2 behavior, primarily academic, while the interview is predicting Years 3 and 4 clinical performance. Controlling for school did not have any impact on the significance of the results for the interview.
The interview scores were also correlated with Openness to Experience (
=.33, r=.19, p<.001) and Extraversion (
=.45, r=.26, p<.001): students who were more intellectually curious and more adept at interpersonal interactions received more favorable scores on the interview. In other words, the interview panel appears to have been influenced by these two personality components of people they were interviewing. They are two factors likely to surface during a forty-five-minute interview.
Personality Factors
Conscientiousness was significantly correlated with five of the seven criterion measures. It predicted both academic and clinical performance across the four years of dental school. It predicted Year 1 performance (r=.24, p<.05), Year 2 clinical performance (r=.47, p<.001), Year 2 academic performance (r=.32, p<.05), Year 3 academic performance (r=.40, p<.001), and Year 4 clinical performance (r=.39, p<.001). Students who are more conscientious performed better in all aspects of their dental training except Year 3 clinical and Year 4 academic work; however, when we controlled for school, Conscientiousness now predicted Year 3 clinical performance (r=.22, p<.05), but still not Year 4 academic coursework (r=.09, n.s.). Partialing out the effects of school had no other effects on the relationships between personality factors and the criterion measures.
Openness to Experience predicted Year 3 academic coursework (r=.24, p<.05); however, when we controlled for the effect of school, this relationship ceased to be significant (r=.16, n.s.). None of the other broad personality factors were significantly correlated with any of the criterion variables, even after controlling for school.
| Discussion |
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The DAT as a Predictor of Performance
Based on previous research, the DAT was expected to be a valid predictor of academic performance. The Academic Average component significantly predicted academic success in the first and second years of dental training, and both the Reading Comprehension and Perceptual Ability components predicted success in first-year academic coursework. These results are generally consistent with previous studies;2,3,31 however, Chamberlain et al.3 found that the DAT did not predict second-year performance, and Smithers et al.2 did not find a relationship between Perceptual Ability and first-year performance. Unexpectedly, the DAT Academic Average predicted Year 2 clinical performance. Cognitive ability may be related to the ability to perform a number of procedures in a clinical setting without attention to quality.3 As the Academic Average component of the DAT is a proxy to a measure of cognitive ability, this may be a reason for why the DAT was predicting third-year clinical performance. Also, we did not expect the DAT Perceptual Ability measure to predict clinical work in the second year. This coursework, however, is the first introduction to dental procedures and the need to use dental mirrors and understand mirror image views; these are abilities directly related to the Perceptual Ability component.
Overall, our results provide further evidence that the DAT, particularly the Academic Average component, is a very good predictor of performance in the first two years of dental training, particularly performance in didactic coursework. Our study strongly supports the continued use of the DAT as a selection tool for dental school.
The CDA Interview as a Predictor of Performance
In our study, the interview correlated significantly with third- (r=.31) and fourth-year (r=.44) clinical performance. Analysis of data collected for this study indicates that the new interview is a valid predictor of clinical performance in dental school. This was one of the reasons for its development. The values reported here for the interview are consistent with those found for selection instruments used in hiring employees, about .30.38 One might ask whether correlations of this size, while significant, are practical. Cohen39 provides guidelines to answer this question. He terms correlations with values of .10, .30, and .50 as constituting small, medium, and large effects, respectively. The uncorrected correlations reported in Table 5
range from .18 to .40, or by Cohens guidelines from small-medium to medium-large effects. Practicality also depends on any capability to predict future performance38; in our case, none of the traditional assessment measures predicted clinical behavior in the third and fourth years, but the interview, conscientiousness, and openness did. That is, the inclusion of a structured interview of the type reported here along with a measure of personality does have practical value.
However we could not test for an increased predictive validity for the Interview beyond that afforded by the DAT; sample size was too small to produce stable results in a hierarchical regression analysis. With more schools joining this project and with an increase in the number of participants at the later years of dental school, we should be able to review the increased contribution of the interview to prediction in future studies. As it stands now, the Interview can predict aspects of clinical performance that cognitive ability, as reflected in the DAT, cannot. In combination with the DAT, it should improve the quality of students admitted into dental school.
In our study, the Interview was also positively associated with Openness to Experience and Extra-version in the Personality Assessment. These results make sense theoretically; the interview panels may be reacting positively to those candidates who are more creative intellectually in responding to the interview questions and rating them more favorably. Similarly, the interviewers may be more responsive to those applicants who exhibit more interpersonal skills during their interviews. While the structured nature of the interview is intended to focus the panels ratings on the nature of the answer, it is likely impossible to keep any aspect of the applicants personality from having some influence on the scoring of their answers.
All the interview teams in this study underwent training and practice before engaging in interviews with the applicants. The training is standardized across all schools using the interview. When we controlled for the possible effects of dental school on the correlation of the interview with our outcome measures, there was little change. This result shows that the training was effective and that the interview teams at the four schools were behaving in much the same fashion. This is an important result as many students apply to several schools and may undergo several interviews. The consistency of the interviews across schools suggests that an interview at one school can suffice with its score entered into a national database much like the DAT scores.
We do note, however, that the interrater reliability for the interview for study participants (r=.67; N=355) was lower than what we obtained across all applicants interviewed to date as part of the interview project, r=.81 (N=1467). This latter value meets the generally accepted reliability standards for selection devices used for decision-making purposes. We believe that the difference between these two values is mostly attributable to learning. We began collecting the longitudinal data for this study at the onset of the project when the interviewers were first asked to learn the new behavioral approach. Even with training, it takes time to adjust to the new process. Since most schools rely on the same set of interviewers, we are not surprised that the interview reliability has increased over time with continued use.
Personality as a Predictor of Performance
The results of this study support the use of the FFM of personality in dental admissions. Conscientiousness predicted academic or clinical performance or both in every year of dental training. These results are in line with previous research on the role of conscientiousness in predicting different aspects of job performance across many occupations (see Hough and Furnham40 for an exhaustive review of this literature). Our study confirms these findings for dental students. Those students who are more conscientious demonstrate higher levels of performance than students who are less conscientious both in the classroom and in the clinic and throughout their tenure in dental school.
Openness to Experience predicted performance in third-year academic coursework. This component reflects such aspects of behavior as being intellectually curious and having a preference for problem solving. Previous research suggested that Openness might not be a characteristic suited to the dental environment, which requires students to follow established procedures. This environment would not be favorable for students who were more creative; rather, students who were more comfortable using established methods and techniques would be more successful. However, recent changes in dental education have focused on more problem-based learning, and those students who are more intellectually curious may be doing much better in those environments. Our previous results2,3 were limited to participants from only two schools. The expanded database in the current study includes students who have experienced dental education strategies at four schools, and the findings may indicate that a wider diversity of instructional strategies are being employed that are more consistent with the personality profiles of contemporary Canadian dental students. Indeed, when we controlled for dental school, the correlation of Openness with Year 3 academic performance became nonsignificant, similar to our previous results for this personality component. Keep in mind that personality was not used as part of the admissions process at any of the participating schools at the time of this study. These results suggest that students with different personality profiles may be attracted to different schools, or they are being accepted differentially across schools.
The broad factors of Agreeableness, Extraversion, and Neuroticism did not predict any of the criteria. In our previous studies, we were able to examine the narrower personality facets contained within the broader factors. We were not able to do that in this study as we had facet data from only two of the participating schools. When we looked at the reduced data set for the personality facets, we found that Straightforwardness, a facet of Agreeableness, predicted second-year academic performance. Impulsiveness, a facet of Neuroticism, predicted first-year performance, second-year academic performance, and third-year academic and clinical performance. There were no significant correlations between facets of Extraversion and the criterion measures.
Overall, the current results are mostly consistent with the results of our previous studies.2,3 Conscientiousness was not as consistent a predictor of performance in prior studies, whereas here, it predicted all criteria except Year 4 academic performance. The most probable reason for the difference in results between this study and those of Chamberlain et al.3 is sample size. The current samples are larger and have increased power to detect significant effects, although the sample size in Year 4 is still relatively small. Additionally, the results across these studies may be sample specific, particularly those concerning the narrow personality facets. Nonetheless, this study builds on previous research and further suggests that personality components are valid predictors of performance in dental school and should be used in the selection of dental students.
| Conclusions and Future Directions |
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It would also be useful to collect personality data from the entire applicant pool and from practicing dentists. Personality data from admitted and non-admitted applicants would allow for a comparison of the personality profiles of those who are not admitted into dental training with successful students who are already enrolled and also with practicing dentists. Using a limited sample of practitioners, Chamberlain et al.3 found that students whose profiles were similar to dentists average profile performed better in the first year of dental school. Further research could help in developing a profile of the ideal dental student, which could be used to improve the selection process.
Future research can also aid the development of a comprehensive database that tracks student performance. This database would allow for an ongoing assessment of the reliability and validity of the admissions criteria with respect to didactic and clinical performance in dental school and to performance on licensing exams. The ability to monitor these linkages would allow identification of those selection criteria that are not performing as well as expected and the opportunity to improve selection practices. Such a longitudinal database would help immensely in developing admissions procedures that are not only valid and reliable, but also current with best practices and focused on success in dental school.
| Acknowledgments |
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| Footnotes |
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| REFERENCES |
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This article has been cited by other articles:
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N. Lopez, K. Self, and J. Karnitz Developing a Tool for Systematic Inclusion of Non-Academic Factors in Dental School Admissions: Towards Building Diversity in the Dental Workforce J Dent Educ., December 1, 2009; 73(12): 1347 - 1352. [Abstract] [Full Text] [PDF] |
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D. A. Curtis, S. L. Lind, O. Plesh, and F. C. Finzen Correlation of Admissions Criteria with Academic Performance in Dental Students J Dent Educ., October 1, 2007; 71(10): 1314 - 1321. [Abstract] [Full Text] [PDF] |
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