The relationship between ambulance team's professional commitment, occupational anxiety, and resilience levels.

BACKGROUND: Individuals who have the ability to bounce back from stressful events, to recover from their troubles and adverse environmental conditions by getting stronger each time are known as resilient people. Some professions may cause more occupational anxiety than others due to their characteristics and working conditions. In this research, we aimed to develop a professional commitment scale for the ambulance team. Another aim was to analyze the relationships between professional commitment, occupational anxiety, resilience, gender, job, seniority and working unit variables. METHODS: In the study, data were collected from a total of 1142 emergency ambulance workers working in Emergency Ambulance and Emergency Call Centers in 34 different cities in Turkey. Data were collected using the "Professional Commitment of Ambulance Team Scale (PCATS), Occupational Anxiety Scale for Emergency Medical Service Professionals (OASEMSP), and Resilience Scale for Adults (RSA). Scale development analyses were carried out using Classical Test Theory (CTT) and Item Response Theory (IRT). Regression analysis were used to examine the relationships between professional commitment, occupational anxiety, resilience, gender, job, seniority and working unit. RESULTS: As a result of the exploratory factor analysis (EFA), it was determined that 8 items remaining in the professional commitment scale formed a single-factor structure, explaining 46% of the variance of professional commitment of the team. The Cronbach's Alpha reliability value was 0.867. Confirmatory factor analysis (CFA) confirmed the results of exploratory factor analysis. The Cronbach's Alpha reliability coefficient obtained through CTT was 0.868, and the marginal reliability coefficient within the scope of IRT was 0.877. The test-retest reliability coefficient was calculated as 0.832, which indicates that the scale is valid and reliable. CONCLUSIONS: The study revealed that resilience has a positive effect for professional commitment while occupational anxiety has a negative effect for professional commitment. In addition, having a moderate seniority has a negative (reducing) effect for professional commitment. Other variables (gender, job, and working unit) was found to have no significant impact on professional commitment.

Evaluation and refinement of Self-Directed Learning Readiness Scale for medical students.

PURPOSE: This study evaluated the underlying subdomain structure of the Self-Directed Learning Readiness Scale (SDLRS) for medical students and refined the instrument to measure the subdomains to provide evidence for construct validity. Developing self-directed learners is a well-recognized goal amongst medical educators. The SDLRS has been frequently used, however, lack of construct validity makes it difficult to interpret results. METHODS: To identify the valid subdomains of the SDLRS, items were calibrated with the graded response model (GRM) and results were used to construct a 30-item short form. Short-form validity was evaluated by examining the correspondence between the total scores from the short form and the original instrument for individual students. RESULTS: A five-subdomain model explained the SDLRS item response data reasonably well. These included: (1) initiative and independence in learning, (2) self-concept as an effective learner, (3) openness to learning opportunity, (4) love of learning, and (5) acceptance for one's own learning. The unidimensional GRM for each subdomain fits the data better than multi-dimensional models. The total scores from the refined short form and the original form were correlated at 0.98 and the mean difference was 1.33, providing evidence for validation. Nearly 91% of 179 respondents were accurately classified within the low, average, and high readiness groups. CONCLUSION: Sufficient evidence was obtained for the validity and reliability of the refined 30-item short-form targeting five subdomains to measure medical students' readiness to engage in self-directed learning.

Ordinal Outcome State-Space Models for Intensive Longitudinal Data.

Intensive longitudinal (IL) data are increasingly prevalent in psychological science, coinciding with technological advancements that make it simple to deploy study designs such as daily diary and ecological momentary assessments. IL data are characterized by a rapid rate of data collection (1+ collections per day), over a period of time, allowing for the capture of the dynamics that underlie psychological and behavioral processes. One powerful framework for analyzing IL data is state-space modeling, where observed variables are considered measurements for underlying states (i.e., latent variables) that change together over time. However, state-space modeling has typically relied on continuous measurements, whereas psychological data often come in the form of ordinal measurements such as Likert scale items. In this manuscript, we develop a general estimation approach for state-space models with ordinal measurements, specifically focusing on a graded response model for Likert scale items. We evaluate the performance of our model and estimator against that of the commonly used "linear approximation" model, which treats ordinal measurements as though they are continuous. We find that our model resulted in unbiased estimates of the state dynamics, while the linear approximation resulted in strongly biased estimates of the state dynamics. Finally, we develop an approximate standard error, termed slice standard errors and show that these approximate standard errors are more liberal than true standard errors (i.e., smaller) at a consistent bias.

The InterModel Vigorish as a Lens for Understanding (and Quantifying) the Value of Item Response Models for Dichotomously Coded Items.

The deployment of statistical models-such as those used in item response theory-necessitates the use of indices that are informative about the degree to which a given model is appropriate for a specific data context. We introduce the InterModel Vigorish (IMV) as an index that can be used to quantify accuracy for models of dichotomous item responses based on the improvement across two sets of predictions (i.e., predictions from two item response models or predictions from a single such model relative to prediction based on the mean). This index has a range of desirable features: It can be used for the comparison of non-nested models and its values are highly portable and generalizable. We use this fact to compare predictive performance across a variety of simulated data contexts and also demonstrate qualitative differences in behavior between the IMV and other common indices (e.g., the AIC and RMSEA). We also illustrate the utility of the IMV in empirical applications with data from 89 dichotomous item response datasets. These empirical applications help illustrate how the IMV can be used in practice and substantiate our claims regarding various aspects of model performance. These findings indicate that the IMV may be a useful indicator in psychometrics, especially as it allows for easy comparison of predictions across a variety of contexts.

The Beck Hopelessness Scale's psychometric features: A new short form based on item response theory.

BACKGROUND: The assessment of hopelessness plays a significant role in preventing various psychological disorders and major life events within the general population. However, the psychometric properties of the Beck Hopelessness Scale (BHS) have been a subject of controversy, primarily studied in clinical groups. The aim of the present study was to gain new psychometric insights and propose a new short version of the BHS for the general population using the Item Response Theory (IRT) approach. METHODS: A total of 2164 Argentinean individuals completed the BHS alongside the Inventory of Suicide Orientation-30. We compared IRT models with two and three parameters for the original BHS version, exploring the removal of redundant and less informative items. Convergent and discriminant validity was also examined. RESULTS: Our results support the 2PL model for the BHS-19. In addition, the BHS-10 short version adequately depicted the same range of the measured trait as the original version, showing reasonable measurement accuracy in the middle-high levels of the trait (marginal reliability = 0.70, Cronbach's α = 0.86). Notably, a positive correlation was found between the factorial score of BHS-10, BHS-19, and suicide orientation. CONCLUSIONS: In conclusion, our findings support the use of a simplified version as a practical and valuable tool for both research and clinical practice in the future.

A novel scale for assessing the risk of low birthweight: Birthweight questionnaire.

BACKGROUND: The birthweight of a newborn is critical to their health, development, and well-being. Previous studies that used maternal characteristics to predict birthweight did not employ a harmonised scale to assess the risk of low birthweight (LBW). OBJECTIVE: The goal of this study was to develop a new instrument that uses items on a uniform scale to assess the risk of an LBW in a pregnant woman. METHODS: Item response theory was employed to evaluate a similar existing scale, and some weaknesses were identified. RESULTS: Based on the observed weaknesses of the existing scale, a new uniform scale was developed, which is a 3-point Likert scale consisting of seven items. CONCLUSION: The scale, termed birthweight questionnaire, is a valuable tool for collecting data that could assist in assessing the risk of an LBW at every stage of pregnancy.

Using a nonparametric item response theory model to identify patterns of cognitive decline: The Mokken scale analysis.

Cognitive decline, particularly in dementia, presents complex challenges in early detection and diagnosis. While Item Response Theory (IRT) has been instrumental in identifying patterns of cognitive impairment through psychometric tests, its parametric models often require large sample sizes and strict assumptions. This creates a need for more adaptable, less demanding analytical methods. This study aimed to evaluate the effectiveness of Mokken scale analysis (MSA), a nonparametric IRT model, in identifying hierarchical patterns of cognitive impairment from psychometric tests. Using data from 1164 adults over 60 years old, we applied MSA to the orientation subscale of ACE-III. Our analysis involved calculating scalability, monotone homogeneity, invariant item ordering (IIO) and response functions. The MSA effectively retrieved the hierarchical order of cognitive impairment patterns. Most items showed strong scalability and consistent patterns of cognitive performance. However, challenges with IIO were observed, particularly with items having adjacent difficulty parameters. The findings highlight MSA's potential as a practical alternative to parametric IRT models in cognitive impairment research. Its ability to provide valuable insights into patterns of cognitive deterioration, coupled with less stringent requirements, makes it a useful tool for clinicians and researchers.

Identifying Disengaged Responding in Multiple-Choice Items: Extending a Latent Class Item Response Model With Novel Process Data Indicators.

Disengaged responding poses a severe threat to the validity of educational large-scale assessments, because item responses from unmotivated test-takers do not reflect their actual ability. Existing identification approaches rely primarily on item response times, which bears the risk of misclassifying fast engaged or slow disengaged responses. Process data with its rich pool of additional information on the test-taking process could thus be used to improve existing identification approaches. In this study, three process data variables-text reread, item revisit, and answer change-were introduced as potential indicators of response engagement for multiple-choice items in a reading comprehension test. An extended latent class item response model for disengaged responding was developed by including the three new indicators as additional predictors of response engagement. In a sample of 1,932 German university students, the extended model indicated a better model fit than the baseline model, which included item response time as only indicator of response engagement. In the extended model, both item response time and text reread were significant predictors of response engagement. However, graphical analyses revealed no systematic differences in the item and person parameter estimation or item response classification between the models. These results suggest only a marginal improvement of the identification of disengaged responding by the new indicators. Implications of these results for future research on disengaged responding with process data are discussed.

Thriving from work questionnaire: German translation and validation.

BACKGROUND: The Thriving from Work questionnaire is a comprehensive indicator of positive well-being for employees, applicable in both research and practical contexts. Current discussions underline the crucial impact that employment should have in enriching workers' lives positively and meaningfully, along with the necessity for accurate and dependable tools to assess employee well-being. This study investigated the reliability, validity, and dimensionality of the translated German adaptation of the Thriving from Work questionnaire developed by Peters and colleagues [1, 2]. The questionnaire assesses work-related well-being with 30 items clustered in six domains: emotional and psychological well-being, social well-being, work-life integration, physical and mental well-being, basic needs for thriving, and experiences of work. METHODS: This study aimed to convert the Thriving at Work Questionnaire from English into German. We assessed the psychometric characteristics of the German version of the questionnaire by using item response theory with a sample of 567 German employees and examined its criterion validity. RESULTS: We found that the long and short German Thriving from Work questionnaire versions are reliable with good construct validity. Criterion validity was demonstrated by relationships with important work and life outcomes, such as life satisfaction, trust in the organizations' management, general well-being, work-related fatigue, and work stress. CONCLUSIONS: The current study demonstrated that the German language version of the questionnaire is both a reliable and valid measure of employee well-being. We discuss recommendations for further adaptation and future research.

Psychometric properties of the health literacy instrument in Brazil (HLS-EU-BR47).

BACKGROUND: Health literacy (HL) is a key component of health promotion and sustainability and contributes to well-being. Despite its global relevance, HL is an under-researched topic in South America but is now debuting its exploration in Brazil. To leverage its benefits for South America, the mere translation of validated tools into Portuguese is insufficient. Rather, it is necessary to examine their validity. This study aims to assess the psychometric properties of the European Health Literacy Questionnaire (HLS-EU-BR47) using the Item Response Theory (IRT) in a population-based sample of adults in Brazil. METHODS: A cross-sectional online study was conducted across Brazil and included 1028 participants aged 18 years and above (80% women). Cronbach's alpha, McDonald's omega, factor analysis, graded responses model, Item Characteristic Curve, HL levels based on this, HL standard calculation, IRT, and regular score correlation were computed. RESULTS: The instrument exhibit high reliability (Cronbach's alpha 0.95). Factor analysis yielded one factor. IRT was appropriate for data analysis because it allowed quality evaluation of items and constructed a scale to quantify HL. The 47 items and latent features of respondents in the same unit of measurement are positioned in the construction of the HLS-EU-BR47 instrument. The percentages of individuals at each HL level, calculated using IRT, were found to be comparable to those obtained through the standard computation, e.g., 3.2% of people reported very low HL versus 10.8% inadequate HL, 56.2% reported low HL versus 39.5% problematic HL, 31.1% had moderate HL versus 30.1% sufficient HL, and 9.5% had high HL versus 19.7% with excellent HL. The mean HL scores were comparable between women and men (33.9 vs. 33.7, P = 0.36). CONCLUSION: This study provides new evidence of the validity of a widely used HL instrument for the population of South America (in this case, Brazil). This tool can be utilized by citizens, health professionals, and regional/national policymakers to inform the development of initiatives to assess and improve the HL of individuals, groups, and communities. Further studies are needed to confirm and extend the findings and to explore the influence of local cultures and practices in the vast Brazilian territory on HL.

Scaling a common assessment of associative ability: Development and validation of a multiple-choice compound remote associates task.

The assessment of creativity as an individual difference has historically focused on divergent thinking, which is increasingly viewed as involving the associative processes that are also understood to be a key component of creative potential. Research on associative processes has proliferated in many sub-fields, often using Compound Remote Associates (CRA) tasks with an open response format and relatively small participant samples. In the present work, we introduce a new format that is more amenable to large-scale data collection in survey designs, and present evidence for the reliability and validity of CRA measures in general using multiple large samples. Study 1 uses a large, representative dataset (N = 1,323,480) to demonstrate strong unidimensionality and internal consistency (α = .97; ωt = .87), as well as links to individual differences in temperament, cognitive ability, occupation, and job characteristics. Study 2 uses an undergraduate sample (N = 685) to validate the use of a multiple-choice format relative to the traditional approach. Study 3 uses a crowdsourced sample (N = 357) to demonstrate high test-retest reliability of the items (r =.74). Finally, Study 4 uses a sample that overlaps with Study 1 (N = 1,502,922) to provide item response theory (IRT) parameters for a large set of high-quality CRA items that use a multiple-choice response mode, thus facilitating their use in future research on creativity, insight, and related topics.

Development and Validation of the Five-Factor Borderline Inventory-Super Short Form and Screener.

The Five-Factor Borderline Inventory (FFBI) and FFBI-Short Form (FFBI-SF) are 120-item and 48-item measures that assess the underlying maladaptive personality traits of borderline personality disorder (BPD). The purpose of this study was to develop a super short form (FFBI-SSF) and an FFBI-Screener to facilitate the use of dimensional trait measures for BPD. Using item response theory analyses, the 48-item measure was reduced to 22 items using a large undergraduate sample (N = 1300) and then retested using a Mechanical Turk sample (N = 602), demonstrating strong replicability. IRT was again used to further reduce the measure from 22 items to four items to provide a brief screening tool. Correlations of the FFBI-SSF and Screener with measures of BPD-related variables were compared across five samples (N = 919, 204, 580, 281, and 488). Overall, the FFBI-SSF showed similar relations to the FFBI-SF at the full scale and domain-level scales, while the FFBI-screener demonstrated similar relations at the full scale level. This super short form and screener may best be used in large-scale research studies or as part of a screening tool in clinical settings.

PROpwr: a Shiny R application to analyze patient-reported outcomes data and estimate power.

Patient Reported Outcomes (PROs) are widely used in quality of life (QOL) studies, health outcomes research, and clinical trials. The importance of PRO has been advocated by health authorities. We propose this R shiny web application, PROpwr, that estimates power for two-arm clinical trials with PRO measures as endpoints using Item Response Theory (GRM: Graded Response Model) and simulations. PROpwr also supports the analysis of PRO data for convenience of estimating the effect size. There are seven function tabs in PROpwr: Frequentist Analysis, Bayesian Analysis, GRM power, T-test Power Given Sample Size, T-test Sample Size Given Power, Download, and References. PROpwr is user-friendly with point-and-click functions. PROpwr can assist researchers to analyze and calculate power and sample size for PRO endpoints in clinical trials without prior programming knowledge.

Psychometric evaluation of the United States-adapted perceived perioperative competence scale-revised: A national survey.

Background: Nursing competence is integral to ensuring patient safety, especially in high-risk environments such as the operating room. Instruments which facilitate self-assessment of specialty specific nursing competence allow nurses to gain important insights into their practice to facilitate continuous growth in their professional practice. Currently, there are no psychometrically tested tools to assess perioperative competence applicable to the United States context. Objective: Test the psychometric properties of the Perceived Perioperative Competence Scale-Revised in the United States context. Methods: A cross-sectional survey design was used. Perioperative nurses were recruited via four professional associations and the survey was administered online. Construct validity of the six-dimensional Perceived Perioperative Competence Scale-Revised was tested using a multidimensional item response theory model known as the graded response model. Measurement invariance was assessed relative to years of perioperative experience. Internal consistency was estimated using McDonald's Omega and Cronbach's alpha reliability coefficients. Results: Responses from a total of 1,581 participants were analyzed in the psychometric analysis. The six-dimensional graded response model of the Perceived Perioperative Competence Scale-Revised displayed satisfactory model fit for the sample (Chi-square(df) = 5,699.09(725); root mean square error of approximation = 0.066, 90% confidence interval: 0.064, 0.067; comparative fit index = 0.955; Tucker-Lewis index = 0.952; standardized root mean squared residual = 0.045). Scalar invariance was established when assessing the psychometric equivalence of the scale across years of perioperative experience (<10 years, ≥ 10 years) (Chi-square(df) = 5,785.29(1,573); root mean square error of approximation = 0.058, 90% confidence interval: 0.057, 0.060; comparative fit index = 0.959; Tucker-Lewis index = 0.959). Reliability across the six subscales ranged from alpha = 0.87 - 0.94 and Omega = 0.93 - 0.97. Conclusions: Results suggest that the Perceived Perioperative Competence Scale-Revised is suitable to use with perioperative nurses practicing in clinical settings in the United States. Measurement invariance testing indicates the scale is measuring the same construct and is being interpreted in a conceptually similar manner across groups based on years of perioperative experience.

Validation of the Barthel Index in Chinese nursing home residents: an item response theory analysis.

Background: The Barthel Index (BI) is used to standardize the grading of assessments for clinical needs, insurance support, and long-term care resource allocation in China. However, its psychometric properties among nursing home residents remain unclear. Therefore, this study aims to assess and modify the psychometric properties of BI in nursing home residents. Methods: A total of 1,402 individuals undergoing evaluation in a nursing home facility in China were included in this study from November 2021 to November 2022. Correlations between items were examined to identify the potential multicollinearity concerns. The unidimensional item response theory (IRT) was used to validate and modify the single structure of BI. Furthermore, the logistic regression/IRT hybrid DIF detection method was conducted to assess differential item functioning (DIF) between the dementia group and the normal group. Results: The pairing of items 5 ("bowl control") and 6 ("bladder control") revealed a local dependence issue, leading to their consolidation. Items 56 (bowel and bladder control) and 9 (mobility) both displayed poor fit indices and underwent category collapsing. Through the application of the generalized partial credit model, the adjusted scale displayed better fit indices, demonstrating a robust discriminative power (DC >1.5) and orderly thresholds. Furthermore, non-uniform DIF was identified in item 2 (bathing) between the dementia group and the normal group. Conclusion: The modified BI demonstrated favorable psychometric properties and proved to be suitable for evaluating nursing home residents experiencing moderate functional impairment, which may provide a precise evaluation for long-term care resource allocation. Future studies could explore integrating supplementary measurements, such as objective indices, to assess a broader spectrum of functional statuses to potentially enhance the limited precision width observed in BI.

The Patient Activation Measure-13 (PAM-13) in an oncology patient population: psychometric properties and dimensionality evaluation.

BACKGROUND: Accurate assessment and enhancement of health-related skills among oncology patients are pivotal for optimizing cancer care. The Patient Activation Measure (PAM-13), a questionnaire designed to reflect an individual's knowledge, skills, and confidence in self-healthcare management, has been validated across diverse countries and settings. Concerns have been raised regarding the cross-situational applicability, as patients with specific diseases and cultural backgrounds interpret questionnaire items differently. This study aimed to examine the structural validity and psychometric properties of the PAM-13 in an oncological patient cohort. METHODS: Baseline data from a longitudinal non-randomized controlled study involving cancer out-patients (n = 1,125) from Comprehensive Cancer Centres in Southern Germany were analysed. The German version of the PAM-13 was employed. With classical test and item response theory methods data quality, reliability, convergent and structural validity, as well as psychometric properties were assessed. Exploratory (EFA) and confirmatory factor analyses (CFA) were employed to investigate the postulated unidimensionality of the underlying construct. With a partial credit model (PCM) we examined item fit, targeting, local independence and differential item functioning. RESULTS: Participants were predominantly female (73.0%) with a breast cancer diagnosis (41.3%). While items were generally well-accepted, ceiling effects were observed and a high mean PAM-13 score (69.7, SD = 14.2) was noted, potentially compromising responsiveness to interventions. Reliability was adequate (Cronbach's α = 0.81), person and item separation reliability were good to excellent (0.81 and 0.99, respectively). Explorations of the unidimensionality of the construct (EFA, CFA, PCM) yielded inconclusive results, hinting towards a two-factor solution. Item difficulty rankings deviated from the original. No differential item functioning was identified, and local independence was confirmed. CONCLUSIONS: While the PAM-13 serves as a valuable instrument for comprehending and promoting health-related skills in cancer patients, the identification of ceiling effects, disordered item-difficulty rankings, and inconclusive findings regarding unidimensionality contribute to the expanding body of evidence, emphasizing the dependency of PAM-13's validity and reliability on distinctive characteristics within the population under investigation. Future research should prioritize refining or adding PAM-13 items to better capture the specific health-related challenges within diverse populations, paving the way for more effective patient engagement strategies in oncology. TRIAL REGISTRATION NUMBER: DRKS00021779.

[Study on the applicability of the Brief Job Stress Questionnaire based on classical test theory and item response theory].

Objective: To evaluate the quality and item characteristics of the Brief Job Stress Questionnaire (BJSQ) among employees in manufacturing and service industries. Methods: From December 2021 to December 2022, a total of 2077 employees from 4 manufacturing and service enterprises in Beijing were selected by the method of combining purpose sampling and convenience sampling. The Chinese version of BJSQ was used to carry out a survey on occupational stress from 57 items in 4 dimensions including job stress factors, stress response, social support factors and satisfaction. Classical test theory (CTT) was used to analyze the validity and reliability of the questionnaire. The Semejima hierarchical response model in item response theory (IRT) was used to analyze the differentiation a, difficulty coefficient b and information content of each item. Results: Among the 2077 subjects, the age M (Q(1), Q(3)) was 33 (28, 37) years old, and the working age M (Q(1), Q(3)) was 4 (2, 8) years. There were 723 (34.8%) people in manufacturing industry and 1354 (65.2%) people in service industry. Eleven common factors were extracted by exploratory factor analysis, with a cumulative variance contribution rate of 62.823%, the variance of the common factors of each entry ranging from 0.451 to 0.865, and the range of factor loading values from 0.413 to 0.825, with 5 items having cross-loadings. The results of the validation factor analysis showed that the model fit indexes of root means square error of approximation was 0.055, comparative fit index was 0.950, Tucker Lewis index was 0.948, and standardized root mean square was 0.066. Content validity results showed that the total scores of the Chinese version of the BJSQ were positively correlated with the scores of the 4 dimensions (r(s)=0.487-0.936, P<0.05) . The results of the reliability analysis showed that the Cronbach's alpha coefficient for the total questionnaire was 0.945, and the Cronbach's alpha coefficients of job stress factors, stress response and social support factors were 0.775, 0.957, and 0.830, respectively. The Spearman-Brown coefficient for the total questionnaire was 0.866, and for the 3 dimensions, it was 0.572, 0.882 and 0.772. The results of IRT analysis showed that only 1 of the 57 items had a differentiation a-value<0.30, the difficulty coefficient b-value of each item ranged from -12.02 to 11.09, of which 8 items had a difficulty coefficient that was too high, 3 items had a difficulty coefficient that was too low, and 3 items did not meet the requirements, and the average amount of information in each item ranged from 0.022 to 2.566, and there were 47 items with average amount of information>0.088 (5/57) . Conclusion: The Chinese version of BJSQ has good reliability and validity in the typical occupational groups of manufacturing and service industries in China, and most of the items have good performance, but some items still need to be further improved and optimized or deleted.

Development and validation of a research version of the Overall Assessment of the Speaker's Experience of Stuttering- Adult (OASES-A-R).

BACKGROUND: The Overall Assessment of the Speaker's Experience of Stuttering for Adults (OASES-A; Yaruss & Quesal, 2016) is a widely used measurement tool designed to evaluate the adverse impact associated with stuttering. Items examine general perceptions of stuttering, personal reactions to stuttering, functional communication difficulties, and consequences for quality of life. This paper presents a shortened research version of the OASES-A response form (OASES-A-R) that can be used by researchers in scientific studies involving adults who stutter that reflect the Section and Total Scores of the original OASES-A using fewer items. METHOD: Previously collected OASES-A data (N = 315) were analyzed via graded response modeling to identify discrimination values of each OASES-A item in measuring each OASES-A Section Total Score. Items with the highest discrimination and items judged by expert clinicians to be more important in measuring adverse impact (N = 27) were used to create a shortened OASES-A-R. The shortened OASES-A-R response form was then validated and compared to the full OASES-A response form in an independent sample (N = 156). RESULTS: The shortened 25-item OASES-A-R response form demonstrated very high and positive correlations with the full OASES-A response form. Similarly, each OASES-A-R Section demonstrated high internal reliability coefficients similar to those of the OASES-A. DISCUSSION: The resulting 25-item OASES-A-R response form provides a reflection of the speaker's experience of stuttering as measured by the original 100-item OASES-A that is suitable for use in certain research studies of adults who stutter. Clinical use is not recommended, as the full OASES-A provides additional insights about a client's experience of stuttering that are necessary for effective treatment planning and intervention.

Differential Item Functioning via Robust Scaling.

This paper proposes a method for assessing differential item functioning (DIF) in item response theory (IRT) models. The method does not require pre-specification of anchor items, which is its main virtue. It is developed in two main steps: first by showing how DIF can be re-formulated as a problem of outlier detection in IRT-based scaling and then tackling the latter using methods from robust statistics. The proposal is a redescending M-estimator of IRT scaling parameters that is tuned to flag items with DIF at the desired asymptotic type I error rate. Theoretical results describe the efficiency of the estimator in the absence of DIF and its robustness in the presence of DIF. Simulation studies show that the proposed method compares favorably to currently available approaches for DIF detection, and a real data example illustrates its application in a research context where pre-specification of anchor items is infeasible. The focus of the paper is the two-parameter logistic model in two independent groups, with extensions to other settings considered in the conclusion.

Incorporating calibration errors in oral reading fluency scoring.

Oral reading fluency (ORF) assessments are commonly used to screen at-risk readers and evaluate interventions' effectiveness as curriculum-based measurements. Similar to the standard practice in item response theory (IRT), calibrated passage parameter estimates are currently used as if they were population values in model-based ORF scoring. However, calibration errors that are unaccounted for may bias ORF score estimates and, in particular, lead to underestimated standard errors (SEs) of ORF scores. Therefore, we consider an approach that incorporates the calibration errors in latent variable scores. We further derive the SEs of ORF scores based on the delta method to incorporate the calibration uncertainty. We conduct a simulation study to evaluate the recovery of point estimates and SEs of latent variable scores and ORF scores in various simulated conditions. Results suggest that ignoring calibration errors leads to underestimated latent variable score SEs and ORF score SEs, especially when the calibration sample is small.