Validation of the National Board Dental Hygiene Examination.

UNLABELLED: The National Board Dental Hygiene Examination program is a part of the process for licensing dental hygienists. The examination assesses theoretical and applied knowledge in the basic biomedical, dental, and dental hygiene sciences, as well as community health. Standards for licensure examinations recommend that test publishers demonstrate a relationship between examination content and actual practice. METHOD: To this end, a validity study was conducted, which involved the definition of the domain of entry-level dental hygiene practice using 56 competencies; the conduct of a practice analysis survey designed to rate the importance of these competencies; and the linking of competencies to content elements in accordance with the competencies' importance ratings. Of the 3941 surveys distributed, 1841 participants responded and, of these, 1284 were full-time practitioners. The importance ratings for the competencies were translated into numbers of items. The number of items devoted to each competency was distributed across all applicable elements of the existing content specifications based upon the knowledge needed to support the realization of the competency. RESULTS AND DISCUSSION: The findings confirmed the adequacy of the content specifications in effect prior to 2005. However, based on this validity study, 2 sub areas of relatively little significance were eliminated, and 2 new areas were introduced. Specifically, Clinical Testing under Assessing Patient Characteristics (one item) and Professional Methods of Administering Fluorides under Using Preventive Agents (one item) were eliminated, and Dental Hygiene Treatment Strategies was incorporated with 4 items, and Professional Responsibilities was added with a total of 28 items.

An investigation of gender differences in the components influencing the difficulty of spatial ability items.

This study examines the role that gender differences play in the determination of the components influencing the difficulty of spatial ability items. Considerable research has examined the role of gender differences in spatial abilities, with sometimes contradictory findings. In general, the findings show that males tend to outperform females on spatial ability items. Other research has focused on determining the components of items that contribute to their difficulty. This research has usually been based on mixed-gender populations, however. The present study attempts to determine if gender influences the extent to which different components contribute to the difficulty of items. The results indicate that component difficulties show very little variation across gender. This finding supports the notion that any differences in raw scores observed for males and females are not due to differences in the manner in which males and females process spatial information or solve spatial ability items.

Value in dental aptitude testing for minority applicants.

Dental Admission Test (DAT) content is designed to be relevant to the scientific material encountered in the dental school curriculum. Before use, all items are examined to ensure that they are equally familiar to all groups participating in the testing program. Moreover, performance on the DAT has been found to be the best nationally available predictor of success in dental school programs. While differential test performance has been observed for the various groups participating in the testing program, the validity of the test is comparable across these groups. Clearly, evidence supports the use of the Dental Admission Test in dental school admissions for all applicants.

Construct validity of the restructured National Board Dental Hygiene Examination.

The construct validity of the restructured National Board Dental Hygiene Examination, as operationalized in the pilot, was examined. The findings show that the examination assesses a full range of relevant content and cognitive behaviors. The results of the principal component analysis of the examination data indicate that the pilot is a unidimensional test of dental hygiene functions. The performances of students on the restructured examination and on the April 1996 dental hygiene examinations were comparable. These findings suggest that the restructured dental hygiene examination will be a valid measure of dental hygiene students' knowledge and problem-solving skills.

Plasma taurine concentrations in normal dogs and in dogs with heart disease.

Plasma taurine concentrations were determined in 76 dogs with dilated cardiomyopathy (DCM), 28 dogs with acquired valvular disease (AVD), and 47 normal (control) dogs. The data were collected at 2 referral centers, The Animal Medical Center, New York, NY (AMC), and the University of California, Davis (UCD), and the studies were conducted independently. Different anticoagulants (sodium citrate at AMC and lithium heparin at UCD) were used to collect the plasma samples. Paired analysis of samples showed a significant difference in plasma taurine concentrations, depending on the anticoagulant used. Consequently, results from each clinic were analyzed separately. Plasma taurine concentrations were significantly higher in dogs with AVD (median, 133 nmol/mL; range, 25 to 229 nmol/mL) than in control dogs (median, 63 nmol/mL; range 44 to 224 nmol/mL) and dogs with DCM (median, 72 nmol/mL; range, 1 to 247 nmol/mL) at AMC (P < .001). The number of dogs with AVD at UCD was too small to draw meaningful conclusions. At UCD, the median plasma taurine concentration was 98 nmol/mL (range, 28-169 nmol/mL) in dogs with AVD, 75 nmol/mL (range, 0.1-184 nmol/mL) in dogs with DCM, and 88 nmol/mL (range 52-180 nmol/mL) in control dogs. There were no significant differences in plasma taurine concentrations between dogs with DCM and the control dogs at either hospital. Congestive heart failure and administration of cardiac medication had no significant effect on plasma taurine concentrations. Plasma taurine concentration was low (< 25 nmol/mL) in 17% (13/76) of the dogs with DCM. Seven of the 13 dogs with low plasma taurine concentrations were Cocker Spaniels or Golden Retrievers.(ABSTRACT TRUNCATED AT 250 WORDS)

Setting a standard on the pilot National Board Dental Examination.

Norm-referenced and criterion-referenced approaches to setting a standard, or minimum passing score, were used with the pilot Part II National Board Dental Examination. The criterion-referenced approach used with the pilot is based on the Rasch measurement model. The standards and associated failure rates were found to be similar for both approaches. These findings as well as the advantages associated with using the Rasch model suggest that this criterion-referenced approach to setting a standard on the restructured Part II examination is appropriate.

Reliability and validity of the pilot National Board Dental Examination.

The reliability and validity of the pilot National Board Dental Examination were examined. The results indicate that the pilot examination is a reliable test that assesses a full range of cognitive behaviors. Furthermore, the findings indicate that the pilot examination is a unidimensional test of comprehensive general dentistry. The performance of examinees on the pilot examination was found to be similar to their performance on the traditional Part II examination. These findings suggest that the restructured Part II examination will be a more reliable and valid measure of dental students' knowledge and problem-solving skills than the traditional Part II.

Incidence of measurement disturbances in the Dental Admission Quantitative Reasoning Test.

This paper describes the incidence of inconsistent person-response patterns in the Quantitative Reasoning Test (QRT), which is part of the Dental Admission Test (DAT) battery. using the Rasch person analysis approach to estimate the likelihood of a response pattern resulting from only two factors (the difficulty of the items and the ability of the person), a statistical profile of inconsistent response patterns was developed for a sample of students taking the DAT. The results of two test dates, April 1987 and October 1988, were included in this study. A random sample of 1,000 persons was drawn from each of these two test administrations. For the Fall 1988 sample, the person analysis was supplemented by a questionnaire designed to check the correspondence between a student's self-reported response behavior and the statistical profile provided by the person analysis. The analysis of the two samples of response patterns indicates a high incidence (50 percent+) of atypical response patterns on the test. This has serious implications for the admissions procedure since many of the atypical response patterns invalidate the standard scores reported for those students.

Gender differences in item performance and predictive validity on the DAT Quantitative Reasoning Test.

This article reports on examination of the performance of males and females on individual items of a graduate admission mathematics test--i.e., the Quantitative Reasoning Test administered as part of the Dental Admission Test--and relates the results to success in dental school. Items that are differentially familiar to males and females were identified and used as independent predictors of success in the first year of dental school. There was no significant difference between male and female performance in dental schools and no significant difference in the predictive validity of items that "favor males" and those that "favor females." Furthermore, the items that "favor females" produce approximately equal raw score distributions for males and females without significant adjustments in the content specifications of the test and thus would not underpredict female performance in dental schools.

Construct and predictive validities of the Perceptual Ability Test.

The construct and predictive validities of the Perceptual Ability Test (PAT) were examined. The results indicate that the PAT is a multidimensional test of spatial abilities, with each of the PAT subtests exhibiting different predictive validity. Furthermore, a linear combination of the PAT subtest scores was found to be more predictive of first-year dental school technique performance than the total PAT score.

Revision of Dental Admission Test standard score scale.

In October 1988 the Dental Admission Testing Program will begin reporting DAT scores on a new standard score scale. This scale will be based on the underlying ability metric rather than on the normal distribution that is the basis of the current-1 to 9 scale. A comparison of the two standard score scales is included, as well as a discussion of the advantages offered by the ability based metric.

Predictive validity of the Dental Admission Test.

The relationship of Dental Admission Test (DAT) scales and predental grade point averages (GPAs) with freshman and sophomore dental school performance measures and National Board Dental Examination (NBDE) Part I averages were examined. The results indicated that the DAT scales had limited predictive validity with respect to summary performance measures and measures in specific disciplines. Furthermore, the DAT contributed information regarding dental school performance beyond that contributed by predental GPAs.

Trends in academic qualifications and performance of dental students.

The academic qualifications and dental school performance measures of students enrolled at public and private dental schools during the five-year period beginning in 1980 were examined. The results indicated that mean DAT academic averages and predental science GPA measures declined significantly over the most recent four years observed. For these qualifications, there were significant differences between those students enrolled at public and private dental schools, with those students enrolled at public schools tending to outperform those at private schools. The results of the analyses of dental school performance measures showed no clear, consistent pattern of decline over the same five-year period.

Globin mRNA translation on Artemia salina ribosomes with components from Friend leukemia cells.

Globin mRNA can be translated with relatively high efficiency in a fractionated cell-free system containing ribosomes prepared from cytst of Artemia salina. These ribosomes have unusually low endogenous activity for peptide synthesis in the absence of added mRNA. The system requires components from the postribosomal supernatant and from the 0.5 M KCl ribosomal wash fraction. Both these fractions were derived from either rabbit reticulocytes or unstimulated Friend leukemia cells that produce little or no hemoglobin. The activity of mRNA and enzyme fractions from rabbit reticulocytes and Friend leukemia cells were tested in this system in vitro for their ability to direct the synthesis of the alpha and beta chains of globin. The alpha:beta chain ratio synthesized from mRNA in the rabbit reticulocyte salt wash fraction was 4:1. The corresponding value for the 9-S mRNA fraction from the salt-washed reticulocyte ribosomes was 1:4, thus these two fractions appear to provide sources enriched in either alpha or beta globin mRNA. Under all conditions tested, the ratio and amounts of peptides formed in vitro appear to reflect mRNA composition. Globin mRNA from dimethysulfoxide-stimulated Friend leukemia cells when translated in vitro produced alpha and beta chains in a ratio of 1:1. These peptides are formed in the same ratio in the intact cells.