Revisiting the 4-Parameter Item Response Model: Bayesian Estimation and Application

There has been renewed interest in Barton and Lord’s (An upper asymptote for the three-parameter logistic item response model (Tech. Rep. No. 80-20). Educational Testing Service, 1981) four-parameter item response model. This paper presents a Bayesian formulation that extends Béguin and Glas (MCMC estimation and some model fit analysis of multidimensional IRT models. Psychometrika, 66 (4):541–561, 2001) and proposes a model for the four-parameter normal ogive (4PNO) model. Monte Carlo evidence is presented concerning the accuracy of parameter recovery. The simulation results support the use of less informative uniform priors for the lower and upper asymptotes, which is an advantage to prior research. Monte Carlo results provide some support for using the deviance information criterion and \(\chi ^{2}\) index to choose among models with two, three, and four parameters. The 4PNO is applied to 7491 adolescents’ responses to a bullying scale collected under the 2005–2006 Health Behavior in School-Aged Children study. The results support the value of the 4PNO to estimate lower and upper asymptotes in large-scale surveys.     

Defining Our Clinical Practice: The Identification of Genetic Counseling Outcomes Utilizing the Reciprocal Engagement Model

The need for evidence-based medicine, including comparative effectiveness studies and patient-centered outcomes research, has become a major healthcare focus. To date, a comprehensive list of genetic counseling outcomes, as espoused by genetic counselors, has not been established and thus, identification of outcomes unique to genetic counseling services has become a priority for the National Society of Genetic Counselors (NSGC). The purpose of this study was to take a critical first step at identifying a more comprehensive list of genetic counseling outcomes. This paper describes the results of a focus group study using the Reciprocal-Engagement Model (REM) as a framework to characterize patient-centered outcomes of genetic counseling clinical practice. Five focus groups were conducted with 27 peer nominated participants who were clinical genetic counselors, genetic counseling program directors, and/or outcomes researchers in genetic counseling. Members of each focus group were asked to identify genetic counseling outcomes for four to five of the 17 goals of the REM. A theory-driven, thematic analysis of focus group data yielded 194 genetic counseling outcomes across the 17 goals. Participants noted some concerns about how genetic counseling outcomes will be measured and evaluated given varying stakeholders and the long-term nature of genetic concerns. The present results provide a list of outcomes for use in future genetic counseling outcomes research and for empirically-supported clinical interventions.     

Genetic Counseling Supervisors’ Self-Efficacy for Select Clinical Supervision Competencies

Supervision is a primary instructional vehicle for genetic counseling student clinical training. Approximately two-thirds of genetic counselors report teaching and education roles, which include supervisory roles. Recently, Eubanks Higgins and colleagues published the first comprehensive list of empirically-derived genetic counseling supervisor competencies. Studies have yet to evaluate whether supervisors possess these competencies and whether their competencies differ as a function of experience. This study investigated three research questions: (1) What are genetic counselor supervisors’ perceptions of their capabilities (self-efficacy) for a select group of supervisor competencies?, (2) Are there differences in self-efficacy as a function of their supervision experience or their genetic counseling experience, and 3) What training methods do they use and prefer to develop supervision skills? One-hundred thirty-one genetic counselor supervisors completed an anonymous online survey assessing demographics, self-efficacy (self-perceived capability) for 12 goal setting and 16 feedback competencies (Scale: 0–100), competencies that are personally challenging, and supervision training experiences and preferences (open-ended). A MANOVA revealed significant positive effects of supervision experience but not genetic counseling experience on participants’ self-efficacy. Although mean self-efficacy ratings were high (>83.7), participant comments revealed several challenging competencies (e.g., incorporating student’s report of feedback from previous supervisors into goal setting, and providing feedback about student behavior rather than personal traits). Commonly preferred supervision training methods included consultation with colleagues, peer discussion, and workshops/seminars.     

Developing a Model of Advanced Training to Promote Career Advancement for Certified Genetic Counselors: An Investigation of Expanded Skills,Advanced Training Paths,and Professional Opportunities

There are currently multiple paths through which genetic counselors can acquire advanced knowledge and skills. However, outside of continuing education opportunities, there are few formal training programs designed specifically for the advanced training of genetic counselors. In the genetic counseling profession, there is currently considerable debate about the paths that should be available to attain advanced skills, as well as the skills that might be needed for practice in the future. The Association of Genetic Counseling Program Directors (AGCPD) convened a national committee, the Committee on Advanced Training for Certified Genetic Counselors (CATCGC), to investigate varied paths to post-master’s training and career development. The committee began its work by developing three related grids that view career advancement from the viewpoints of the skills needed to advance (skills), ways to obtain these skills (paths), and existing genetic counselor positions that offer career change or advancement (positions). Here we describe previous work related to genetic counselor career advancement, the charge of the CATCGC, our preliminary work in developing a model through which to view genetic counselor advanced training and career advancement opportunities, and our next steps in further developing and disseminating the model.     

Performance of Asian elephants (Elephas maximus) on a quantity discrimination task is similar to that of African savanna elephants (Loxodonta africana)

Animal Cognition - Using an object-choice task, we measured the relative quantity discrimination ability of Asian elephants. Two zoo-housed elephants were given auditory cues of food being dropped...     

Inferring the Number of Attributes for the Exploratory DINA Model

Psychometrika - Diagnostic classification models (DCMs) are widely used for providing fine-grained classification of a multidimensional collection of discrete attributes. The application of DCMs...     

Using the Criterion-Predictor Factor Model to Compute the Probability of Detecting Prediction Bias with Ordinary Least Squares Regression

The study of prediction bias is important and the last five decades include research studies that examined whether test scores differentially predict academic or employment performance. Previous studies used ordinary least squares (OLS) to assess whether groups differ in intercepts and slopes. This study shows that OLS yields inaccurate inferences for prediction bias hypotheses. This paper builds upon the criterion-predictor factor model by demonstrating the effect of selection, measurement error, and measurement bias on prediction bias studies that use OLS. The range restricted, criterion-predictor factor model is used to compute Type I error and power rates associated with using regression to assess prediction bias hypotheses. In short, OLS is not capable of testing hypotheses about group differences in latent intercepts and slopes. Additionally, a theorem is presented which shows that researchers should not employ hierarchical regression to assess intercept differences with selected samples.     

Gay, Lesbian, and Bisexual Patients’ Recommendations for Genetic Counselors: A Qualitative Investigation

Gay, lesbian, and bisexual (GLB) individuals comprise a growing patient population in genetic counseling. However, only one article from a genetic counseling journal provides empirical data on GLB patients' genetic counseling experiences and genetic counselor attitudes and practices regarding GLB patients. The present study, an extension of the aforementioned article, gathered further information about patients' genetic counseling experiences through semi-structured telephone interviews. Twelve of the previous study's 29 patient respondents (n?=?10 lesbian women, n?=?1 gay man, n?=?1 bisexual woman) participated. Interview questions concerned the use of medically inclusive forms, factors influencing patient disclosure, counselors' ability to relate to them, and their expectations of genetic counselors. Inductive analysis of the interviews yielded seven themes: 1) Medically inclusive forms with gender neutral terms are important; 2) Genetic counselor ability to relate to a GLB person depends more on the relationship established during the session and less on external symbols; 3) The presence of GLB-friendly symbols increases comfort when disclosing one's orientation; 4) Inclusion of the patient's partner is important and best done by encouraging their active participation in sessions; 5) When GLB patients disclose their orientation, they expect to be treated like any other patient; 6) Providers should ask about orientation if medically pertinent and the remaining discussion should take orientation into consideration; and 7) When a provider inquires about orientation it should be done in a safe and appropriate way. Illustrative quotations, genetic counseling practice implications, and research recommendations are presented.