Using Rasch modeling to measure acculturation in youth

Ethnic differences in health outcomes are assumed to reflect levels of acculturation, among other factors. Health surveys frequently include language and social interaction items taken from existing acculturation instruments. This study evaluated the dimensionality of responses to typical bilinear items in Latino youth using Rasch modeling. Two seven-item scales measuring Anglo-Hispanic orientation were adapted from Marin and Gamba (1996) and Cuellar, Arnold, and Maldonado (1995). Most of the items fit the Rasch model. However, there were gaps in both the Hispanic and Anglo scales. The Anglo items were not well targeted for the sample because most students reported they always spoke English. The lack of variability found in a heterogeneous sample of Latino youth has negative implications for the common practice of relying on language as a measure of acculturation. Acculturation instruments for youth probably need more sensitive items to discriminate linguistic differences, or to measure other factors.     

Using the Rasch model to validate stages of understanding the energy concept

In recent years, there have been efforts to bridge science education with developmental psychology to develop theories on students developing understanding of science concepts from elementary to high school and beyond. The present study intends to test one such theory on students developing understanding of the energy concept. The theory states that students develop understanding of the energy concept by going through the following qualitatively distinct stages: (a) energy as activity/work; (b) energy as sources/forms, (c) energy transfer, (d) energy degradation, and (e) energy conservation. Three classes, one each from 4th grade, 8th grade, and high school physics class (grades 10, 11, and 12), completed a performance assessment. Students' performances were scored based on three traits of energy understanding: attention capacity, qualitative relations, and quantitative relations; each of the traits was defined into five hierarchical levels consistent with the five stages of understanding the energy concept. The Many-Facet Rasch Measurement (MFRM) model was used to analyze the effects of rater scoring severity, students' stages of energy understanding (theta), and difficulties of energy understanding traits. Results show that there was a discontinuity among the stages of understanding the energy concept, supporting the theory on students developing the understanding of the energy concept.     

Using a multidimensional Rasch model approach to measure the police's perceived ability to detect,detain and intercept DWI vehicles when conducting sobriety checkpoints

This study developed a scale to measure 502 Taiwan traffic police officers’ perceived ability to detect, detain, and intercept those vehicles whose drivers are driving while intoxicated (DWI) when conducting sobriety checkpoints. Through factor analysis, the officers’ enforcement ability was found to consist of two component latent traits: detecting ability (DA) and detaining and intercepting ability (DIA). A multidimensional approach of Rasch models was then applied to measure the police officers’ perceived abilities and particular difficulties in conducting sobriety checkpoints. The study results indicated that the majority of police officers performed well in detecting DWI vehicles, but half of the study participants lacked confidence in detaining DWI vehicles and intercepting escaping DWI vehicles. DWI with weaving was found to be the most aggressive and threatening behavior to traffic police when conducting sobriety checkpoints. Police officers over age 46 were found to have significantly lower DA and DIA, while branch captains were found to have significantly higher DA than their colleagues. Several strategies and programs are suggested based on the study findings to improve the enforcement ability of police officers.     

Using the Rasch measurement model to investigate the construct of motor ability in young children

This paper reports the use of a Rasch measurement model, the Extended Logistic Model of Rasch (Andrich, 1988), to explore the construct of a general motor ability in young children. Data were collected from 332 five and six year old children performing 24 motor skills, including run, hop, balance and ball skills. The data were categorised based on threshold estimates provided by the measurement model. Gender differences in performances on items were hypothesised to contribute to initial item and person misfit for the total sample. The data for boys and for girls were separated and independently analysed resulting in improved item and person fit. Two different, unidimensional scales for boys and for girls were created.     

Using Rasch models to reveal contours of teachers' knowledge

Teachers' knowledge is usually categorised into subject matter (SMK) and pedagogical content knowledge (PCK). Previously, measurement instruments and consequent cognitive scales have been developed to assess students' and teachers' subject knowledge. A number of qualitative studies have explored teachers' pedagogical content knowledge. This study developed a means to investigate one aspect of PCK--teachers' awareness of their students' knowledge--using a combination of measurement and qualitative interpretation. We asked teachers to estimate on a Likert scale (and also describe qualitatively) the difficulty their pupils would have with test items which we had already scaled using data from their pupils. We then constructed, using various models, a "Teacher's collective Perception of Item Difficulty" (TPID) scale and contrasted this with the student's ability scale by comparing the two sets of item-difficulty parameters. The results were triangulated with qualitative data. We suggest the methodology is best supported by an Inverse Partial Credit Model (IPCM) but we compare the results across alternative Rasch models.     

标准化是发展农业和农村经济的重要措施

一、前言农业标准化是以农业科学技术和实践经验为基础,运用简化、统一、协调、优选的原理,把科研成果和先进技术转化成标准,并加以实施,取得好的经济效益和社会效果。标准化是农业和农村经济发展,农业产业化、现代化建设必不可少的一项重要工作。农业现代化的主要特...     

Using Rasch analysis to construct a Clinical Problem-Solving Inventory in the dental clinic: a case study

A 28-item inventory was developed to measure the clinical problem-solving abilities of 3rd and 4th year dental students. The judgments of 57 expert raters (dental-school faculty) from four dental schools used the inventory to evaluate 183 dental students on a 5-point rating scale. The Rasch measurement model was employed to examine the psychometric properties and construct validity of this inventory. In this study, fit statistics identified the "noise" in the data and residual analysis assisted in extracting a meaningful structure. The study results indicate that the Rasch measurement model appeared to be a useful method for use in producing a unidimensional instrument. All five rating categories were used in a coherent manner, and four discernable levels of clinical problem-solving ability were identified. After removal of four repetitious items, a version of the Clinical Problem-Solving Inventory was finalized that could serve as a criterion measure for validating the use of a critical thinking test on the Dental Admission Test.     

Evidence for the reliability of measures and validity of measure interpretation: a Rasch measurement perspective

In an era of high stakes testing and evaluation in education, psychology, and health care, there is need for rigorous methods and standards for obtaining evidence of the reliability of measures and validity of inferences. Messick (1989, 1995), the Standard for Educational and Psychological Testing (American Psychological Association, American Educational Research Association, and National Council on Measurement in Education, 1999), and the Medical Outcomes Trust (1995), among others, have described methods that may be used to gather evidence for reliability and validity, but ignored the potential role Rasch measurement may contribute to this process. This article will outline methods in Rasch measurement that are used to gather evidence for reliability and validity and attempt to articulate how these methods may be linked with the current views of reliability and validity.     

Diagnosing a common rater halo effect using the polytomous Rasch model

The 'halo effect' may be unique to different raters or common to all raters. When common to all raters, halo is not detectable through standard fit indices of the three-facet Rasch model used to account for differences in rater severities. Using a formulation of halo as a violation of local independence, a halo effect common to all raters is simulated and shown to be diagnosable through contrasts between two-facet stack and rack Rasch analyses. In the former, the thresholds are clustered and the distribution of persons is multimodal; in the latter, all thresholds are close together and the distribution of persons is unimodal. In the former, the scale is stretched, and the person separation inflated, relative to the latter.     

Using microwave multimeters to measure the parameters of dielectrics

A method of nondestructive measurement of the complex dielectric constant using a microwave multimeter and probe antennas is described.Translated from Izmeritel'naya Tekhnika, No. 6, pp. 49–52, June, 1995.     

Congruence between a theoretical continuum of masculinity and the Rasch model: examining the Conformity to Masculine Norms Inventory

The purpose of this study was to examine the psychometric structure of the Conformity to Masculine Norms Inventory (CMNI) in relation to the Rasch model. The CMNI was specifically constructed to measure a set of unidimensional constructs. As such, the items were intended to define a uniform spread of locations along each construct. The CMNI measures conformity to twelve masculine norms: winning, emotional control, risk-taking, violence, dominance, playboy, self-reliance, primacy of work, power over women, disdain for homosexuals, physical toughness, and pursuit of status. Three hundred forty-eight men participated in the study. In addition to examining global Rasch characteristics and the unidimensionality of each of the 12 scales, a detailed Rasch rating scale analysis is provided for the Violence Scale with unusual response patterns discussed in terms of their clinical usefulness. The results across all 12 scales reveal an excellent congruence between the theoretically derived construct of conformity to masculine norms and the theoretically defined objectives of the Rasch rating scale model.     

Using rainbow net simulation to measure fault tolerance in a multiprocessor

The Rainbow net simulation technique is applied to modelling the impact of system load and fault handling on the availability of a fault-tolerant multiprocessor architecture. Rainbow nets are described along with the motivation for creating this modelling technique. A Rainbow net fault-handling model is created for the fault-tolerant multiprocessor architecture and the topology is shown to remain constant in size, independent of the number of processor, memory and I/O elements configured in the system. Simulation is performed with a varying load in terms of the number of active jobs the system must support. Results are given showing how the fault-tolerant capability varies with load. Two new metrics for evaluating fault tolerance are introduced; namely full fault-tolerability and partial fault-tolerability. They are based on simple observations in the model.     

An approach to studying scale for students in higher education: a Rasch measurement model analysis

A questionnaire comprising 80 self-report items was designed to measure student Approaches to Studying in a higher education context. The items were conceptualized and designed from five learning orientations: a Deep Approach, a Surface Approach, a Strategic Approach, Clarity of Direction and Academic Self-Confidence, to include 40 attitude items and 40 corresponding behavior items. The study aimed to create a scale and investigate its psychometric properties using a Rasch measurement model. The convenience sample consisted of 350 students at an Australian university in 1998. The analysis supported the conceptual structure of the Scale as involving studying attitudes and behaviors towards five orientations to learning. Attitudes are mostly easier than behaviors, in line with the theory. Sixty-eight items fit the model and have good psychometric properties. The proportion of observed variance considered true is 92% and the Scale is well-targeted against the students. Some harder items are needed to improve the targeting and some further testing work needs to be done on the Surface Approach. In the Surface Approach and Clarity of Direction in Studying, attitudes make a lesser contribution than behaviors to the variable, Approaches to Studying.     

Using the Mixed Rasch Model to analyze data from the beliefs and attitudes about memory survey

In this study, we used the Mixed Rasch Model (MRM) to analyze data from the Beliefs and Attitudes About Memory Survey (BAMS; Brown, Garry, Silver, and Loftus, 1997). We used the original 5-point BAMS data to investigate the functioning of the "Neutral" category via threshold analysis under a 2-class MRM solution. The "Neutral" category was identified as not eliciting the model expected responses and observations in the "Neutral" category were subsequently treated as missing data. For the BAMS data without the "Neutral" category, exploratory MRM analyses specifying up to 5 latent classes were conducted to evaluate data-model fit using the consistent Akaike information criterion (CAIC). For each of three BAMS subscales, a two latent class solution was identified as fitting the mixed Rasch rating scale model the best. Results regarding threshold analysis, person parameters, and item fit based on the final models are presented and discussed as well as the implications of this study.     

Measuring attitudes and behaviors to studying and learning for university students: a Rasch measurement model analysis

A Studying and Learning Scale was created using a model of Motivation (sets of ordered stem-items based on Striving for Excellence, Desire to Learn and Personal Incentives), with each item answered from three self-reported perspectives (an Ideal Self-view, a Capability Self-view, and a Studying and Learning Self-view). The response categories were the number of subjects studied. The stem-item sample was 23, each answered in three aspects, so each stem-item had three 'difficulties', making an effective item sample of 69. The person convenience sample was 372 students in education at an Australian university. The 69 items fit a Rasch measurement model and formed a scale in which the 'difficulties' of the items were ordered from 'easy' to 'hard' and the student measures of Studying and Learning were ordered from 'low' to 'high'. The person separation reliability was high at 0.94. The response categories were answered consistently and logically and the results supported many (but not all) of the conceptually ordered-by-difficulty item patterns. Students found it 'easy' to form a high view of How they would like to be, much 'harder' to form a high view of What they think they are capable of doing and even 'harder' to perform, at a high level, their Studying and Learning behavior for all stem-items, in accordance with the model.     

Using a quality scorecard to measure and improve medical groups' performance.

BACKGROUND: Blue Cross of California (BCC) uses an annual Quality Scorecard to measure performance of participating medical groups (PMGs) and independent practice associations (IPAs). The scorecard provides information to the PMGs/IPAs on their performance in several domains relative to the average network score. BCC pays annual bonuses to PMGs/IPAs with superior quality performance. A structured intervention was designed to improve the performance of PMGs/IPAs that performed poorly on the scorecard. METHODS: A cohort study was conducted in a large health maintenance organization in California in 1997. All PMGs/IPAs received a detailed summary of the components of the annual quality scorecard. Scorecard components include an annual audit of quality, utilization management, credentialing, and members' rights and responsibilities, grievance rates, member transfer for quality reasons, a satisfaction survey, and a preventive health review. Twenty-two of 124 PMGs/IPAs with more than 1,000 BCC members during 1996 that had scored lower than 1 standard deviation below the mean were targeted. These 22 outlier PMGs/IPAs received additional information indicating that their performance was below average. A BCC quality team subsequently visited the outlier PMGs/IPAs to provide supplementary information on the deficient areas and provide assistance in making improvements. RESULTS: The outlier groups showed significant improvements in the annual audit of quality score, member satisfaction with access, member satisfaction with last visit, overall member satisfaction with PMGs/IPAs, mammography screening, and the total score. CONCLUSIONS: A structured quality improvement intervention in poorly performing PMGs/IPAs was followed by improvements in specific performance measures.     

Estimating parameters in the Rasch model in the presence of null categories

A category with a frequency of zero is called a null category. When null categories are present in polytomous responses, then in the Rasch model for such responses, the thresholds that define the categories are inestimable with the commonly used joint maximum likelihood, marginal maximum likelihood, or standard conditional maximum likelihood estimation algorithms. The reason for this situation is that in principle, these estimation algorithms involve frequencies of each category. Andrich and Luo (2003) describe an algorithm in which the thresholds are reparameterized into their principal components and in which the estimate of any threshold is based on a function of the frequencies of all categories of the item rather than the frequency of a particular category. This algorithm works in the presence of null categories. However, in situations where the null categories are at the extremes of a set of categories, the estimates themselves can become too extreme. This paper describes a procedure in which the solution algorithm described by Andrich and Luo is further adapted in the presence of null categories by using their expected frequencies. The procedure is demonstrated with simulated and real data.     

Developing a multi-quality characteristic analysis model to measure the quality of quick-release bicycle hubs

To reduce the pollution caused by the carbon emissions of automobiles and locomotive vehicles, many countries around the world have encouraged citizens to use bicycles for short-distance trips in recent years. Bicycles are comprised of many parts, and quick-release hubs are highly important for the fixtures on the front and rear wheel axles of a bicycle. The quick-release hub is a multi-quality characteristic product, including two larger-the-better quality characteristics (quick-release stroke and tensile strength) and three nominal-the-best quality characteristics (axis size, assembly distance, and the outer diameter of the spindle). To improve the quality of quick-release hubs, this study proposes a multi-quality characteristic analysis table (MQCAT) and a multi-quality characteristic analysis model (MQCAM). The proposed method can provide a valuable reference by which to guide efforts aimed at improvement for quick-release hub manufacturers. A quick-release hub manufacturer in central Taiwan is presented to illustrate the feasibility of the proposed method. In addition, a comparison with recent methods is provided to demonstrate the advantages of the proposed method. Finally, conclusions are made based on the research study findings.