Biomedical subjects

E W Wolfe

Publications and source records attributed to E W Wolfe.

6 recordsLinked to original sources

PubMed2001

Detecting differential rater functioning over time (DRIFT) using a Rasch multi-faceted rating scale model.

This paper describes a class of rater effects that depict rater-by-time interactions. We refer to this class of rater effects as DRIFT differential rater functioning over time. This article describes several types of DRIFT (primacy/recency, differential centrality/extremism, and practice/fatigue) and Rasch measurement procedures designed to identify these types of DRIFT in rating data. These procedures are applied to simulated data and are shown to be useful in classifying raters as being aberrant or non-aberrant for primacy, recency, and differential centrality and extremism, particularly for moderate or larger effect sizes. Rates of correct classification for practice and fatigue were lower and statistical power exceeded.50 only with very large effect sizes. Type I error rates (i.e., incorrect nomination) were near expected levels in all cases.

Decision Theory↗

PubMed2000

Development of a scale for measuring invasive plant environmentalism.

The ecological impact of invasive plant species is a serious concern among environmental scientists and conservationists. Educating the public about invasive plant issues is a major hurdle, given that several invaders come into the environment through ornamental gardening. An important first step in planning an educational program concerning invasive plant issues is to assess public knowledge and attitudes concerning these issues. This paper describes the development of an instrument that measures invasive plant environmentalism. Responses from 237 nursery customers from the southeastern U.S. to a 17-item standardized interview were scaled using the partial credit model, a member of the family of Rasch (1960) measurement models. Our results indicate that the instrument adequately measures this construct. Substantive interpretations of the results are also discussed.

Attitude↗

PubMed2000

Development of a nutrition self-efficacy scale for prospective physicians.

Diet is associated with 5 of the 10 leading causes of death in the U.S., including coronary heart disease, certain types of cancer, atherosclerosis, and type 2 diabetes. Physicians can play a pivotal role in promoting nutritional management of diabetes and other chronic diseases. Therefore, it is important that valid instruments are created so administrators can better assess the educational needs of prospective physicians, their practices, and patient outcomes. Two comparable studies, one year apart, were undertaken to create an instrument that measures nutritional competence and self-efficacy among prospective physicians. This paper: (a) describes the development of a nutrition self-efficacy scale (NSES) and (b) demonstrates reliability and validity of the NSES using Rasch modeling. It concludes with a discussion of potential contributions of this scale for assessing mastery of applied nutrition among prospective physicians.

Adult↗

PubMed2000

Equating and item banking with the Rasch model.

This article describes Rasch measurement procedures for equating multiple test forms or calibrating an item bank. The procedures entail (a) selecting an appropriate data collection design, (b) estimating parameters, (c) transforming the parameters from multiple forms to a common scale, and (d) evaluating the quality of the linkage between these forms. Data collection designs include (a) anchor tests, (b) single group, (c) single data set, and (d) equivalent groups. Estimation procedures may involve (a) separate or (b) simultaneous calibration of data from multiple forms. Transformation is typically accomplished using (a) estimation scaling, but may involve (b) parameter anchoring or (c) computing equating constants. Link quality is evaluated using four fit indices: (a) item-within-link, (b) item-between-link, (c) link-within-bank, and (d) form-within-bank. These procedures are illustrated using an anchor test design.

Data Collection↗

PubMed1999

Measuring pretest-posttest change with a Rasch Rating Scale Model.

When measures are taken on the same individual over time, it is difficult to determine whether observed differences are the result of changes in the person or changes in other facets of the measurement situation (e.g., interpretation of items or use of rating scale). This paper describes a method for disentangling changes in persons from changes in the interpretation of Likert-type questionnaire items and the use of rating scales (Wright, 1996a). The procedure relies on anchoring strategies to create a common frame of reference for interpreting measures that are taken at different times and provides a detailed illustration of how to implement these procedures using FACETS.

Educational Measurement↗

PubMed1999

Measuring change across multiple occasions using the Rasch Rating Scale Model.

When latent trait models are used to measure change across time, it is difficult to disentangle changes in one facet of the measurement context from changes in other facets. Hence, it is difficult to diagnose change. Wright (1999b) proposed an algorithm for disentangling change, and previously the authors applied this algorithm to measuring change across two occasions (Wolfe and Chiu, 1999). In this article we extend Wright's algorithm to disentangle changes in measures across three occasions. We describe a standard Rasch rating scale analysis of a multi-occasion evaluation that produces confusing results when subjected to a series of "separate" calibrations. Then, we apply Wright's correction to the same data to show that the algorithm reveals changes that are more similar to ones that would be expected. Our demonstration shows that Wright's procedure can reduce misfit to the Rasch Rating Scale Model as well as changing the interpretation of change within the measurement context.

Algorithms↗