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.

Dyadic analysis of illness perceptions among individuals with stroke and their caregivers: effects on activity engagement in community living.

PURPOSE: To explore the relationship between activity engagement and dyadic illness perceptions of community-dwelling individuals with stroke and their caregivers. METHODS: We performed a secondary analysis on a cross-sectional study encompassing eight rehabilitation settings. Participants were recruited from June to December 2019 via the distribution of flyers, use of admission databases, and direct onsite interactions. Activity engagement of individuals with stroke was measured by the Assessment of Life Habits. Dyadic illness perceptions were measured using the Stroke-Specific Illness Perceptions Questionnaire-Revised. RESULTS: Data from 202 dyads of individuals with stroke (mean age 61.3 ± 8.3 years; 76.7% male; stroke duration 314.3 ± 170.5 days), and caregivers (mean age 52.6 ± 11.6 years; 73.3% female) were analyzed. Results show that individuals with stroke who shared similar optimistic illness perceptions with their caregivers concerning the consequences of stroke had a higher level of activity engagement (ΔR2 = .020, F(2,193) = 5.42, p = .005). Gender differences were found in the dyadic illness perception components concerning acute/chronic and cyclical timeline (ΔR2 = .017, F(2,191) = 4.72, p = .01; ΔR2 = .02, F(2,190) = 3.45, p = .034) and illness coherence (ΔR2 = .012, F(2,191) = 3.42, p = .035). CONCLUSIONS: Illness perceptions and post-stroke activity engagement with gender differences should be considered at a dyadic level, as the individuals with stroke and their caregivers influence each other's beliefs.

Implications for rehabilitationActivity engagement in individuals with stroke is related to how their individual­caregiver dyads perceive their health condition.Clinicians should provide opportunities for individuals with stroke and caregivers to better understand the nature of stroke, and to develop positive outlooks for the future. This information includes, but is not limited to, the relevant sequelae, stroke development and prognosis, treatment and rehabilitation protocols, and the potential impact on daily living.Depending on their genders, individuals with stroke may require different approaches to facilitate community-dwelling activity engagement. Future research is needed to determine the effect of dyadic illness perceptions on post-stroke activity engagement among individuals of different genders.

Poststroke activity engagement in community dwellers: Association with illness perceptions and perceived environment.

OBJECTIVES: To investigate whether individuals' poststroke activity engagement is associated with their perceptions of stroke, as well as their perceptions of physical and social environment. DESIGN: Cross-sectional study. SETTING: Participants were recruited from eight rehabilitation settings in Beijing, China. PARTICIPANTS: A total of 202 dyads of community dwellers with stroke and their primary caregivers. MAIN MEASURES: Activity engagement measured by the Assessment of Life Habits; stroke individuals' and caregivers' illness perceptions measured by the Stroke-Specific Illness Perceptions Questionnaire - Revised; and stroke individuals' perceived social and physical environment measured by the Social Support Survey and abbreviated Neighborhood Environment Walkability Scale. RESULTS: A total of 202 dyads of individuals with stroke and their caregivers participated in the study with mean ages of 61.3 (8.3) and 52.6 (11.6), respectively. On average, stroke individuals scored 7.61 (1.42) on the daily activities subscale, indicating that they completed personal level activities without assistance but with some difficulty. They scored 6.21 (2.21) on the social roles subscale, suggesting that individuals completed societal level activities with assistive devices and with some difficulty. Illness perceptions correlated significantly with personal level activity engagement (change in R-squared = 0.029; p = 0.049), and perceived accessibility and heterogeneity correlated significantly with societal level activity engagement (change in R-squared = 0.025; p = 0.011). CONCLUSIONS: Poststroke activity engagement is associated not only with stroke individuals' performance skills but also with their perceptions of stroke, and how they perceive their physical environment. The findings may assist clinicians' decision making when developing comprehensive, targeted interventions for improving activity engagement and maximizing recovery after stroke.

Mobile health school screening and telemedicine referral to improve access to specialty care in rural Alaska: a cluster- randomised controlled trial.

BACKGROUND: School-based programmes, including hearing screening, provide essential preventive services for rural children. However, minimal evidence on screening methodologies, loss to follow-up, and scarcity of specialists for subsequent care compound rural health disparities. We hypothesised telemedicine specialty referral would improve time to follow-up for school hearing screening compared with standard primary care referral. METHODS: In this cluster-randomised controlled trial conducted in 15 rural Alaskan communities, USA, we randomised communities to telemedicine specialty referral (intervention) or standard primary care referral (control) for school hearing screening. All children (K-12; aged 4-21 years) enrolled in Bering Straight School District were eligible. Community randomisation occurred within four strata using location and school size. Participants were masked to group allocation until screening day, and assessors were masked throughout data collection. Screening occurred annually, and children who screened positive for possible hearing loss or ear disease were monitored for 9 months from the screening date for follow-up. Primary outcome was the time to follow-up after a positive hearing screen; analysis was by intention to treat. The trial was registered with ClinicalTrials.gov, NCT03309553. FINDINGS: We recruited participants between Oct 10, 2017, and March 28, 2019. 15 communities were randomised: eight (750 children) to telemedicine referral and seven (731 children) to primary care referral. 790 (53·3%) of 1481 children screened positive in at least one study year: 391 (52∤1%) in the telemedicine referral communities and 399 (50∤4%) in the primary care referral communities. Of children referred, 268 (68·5%) in the telemedicine referral communities and 128 (32·1%) in primary care referral communities received follow-up within 9 months. Among children who received follow-up, mean time to follow-up was 41·5 days (SD 55·7) in the telemedicine referral communities and 92·0 days (75·8) in the primary care referral communities (adjusted event-time ratio 17·6 [95% CI 6·8-45·3] for all referred children). There were no adverse events. INTERPRETATION: Telemedicine specialty referral significantly improved the time to follow-up after hearing screening in Alaska. Telemedicine might apply to other preventive school-based services to improve access to specialty care for rural children. FUNDING: Patient-Centered Outcomes Research Institute.

Multidimensional Item Response Theory in the Style of Collaborative Filtering.

This paper presents a machine learning approach to multidimensional item response theory (MIRT), a class of latent factor models that can be used to model and predict student performance from observed assessment data. Inspired by collaborative filtering, we define a general class of models that includes many MIRT models. We discuss the use of penalized joint maximum likelihood to estimate individual models and cross-validation to select the best performing model. This model evaluation process can be optimized using batching techniques, such that even sparse large-scale data can be analyzed efficiently. We illustrate our approach with simulated and real data, including an example from a massive open online course. The high-dimensional model fit to this large and sparse dataset does not lend itself well to traditional methods of factor interpretation. By analogy to recommender-system applications, we propose an alternative "validation" of the factor model, using auxiliary information about the popularity of items consulted during an open-book examination in the course.

Measuring early learning and development across cultures: Invariance of the IDELA across five countries.

Relatively little research has addressed whether conceptual frameworks of early learning generalize across different national contexts. This article reports on a cross-country measurement invariance analysis of the International Development and Early Learning Assessment (IDELA). The IDELA is a direct assessment tool for 3- to 6-year-old children, intended to measure Early Literacy, Early Numeracy, Motor, and Social-Emotional development. Its generalizability is evaluated using samples from 5 countries: Afghanistan (N = 2,629); Bolivia (N = 480); Ethiopia (N = 682); Uganda (N = 504); and Vietnam (N = 675). The 4-domain model of the IDELA was supported in each country, although the domains were highly correlated. Measurement invariance analysis revealed that most IDELA items do not provide a basis for comparing children's development over the 5 countries. This research supports the use of the IDELA for program evaluation and within-country monitoring purposes, but cautions against its use for international comparisons. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Psychometric Models of Small Group Collaborations.

The social combination theory of group problem solving is used to extend existing psychometric models to collaborative settings. A model for pairwise group work is proposed, the implications of the model for assessment design are considered, and its estimation is addressed. The results are illustrated with an empirical example in which dyads work together on a twelfth-grade level mathematics assessment. In conclusion, attention is given to avenues of research that seem most fruitful for advancing current initiatives concerning the assessment of collaboration, teamwork, and related constructs.

Myalgic encephalomyelitis/chronic fatigue syndrome and gulf war illness patients exhibit increased humoral responses to the herpesviruses-encoded dUTPase: Implications in disease pathophysiology.

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and Gulf War Illness (GWI) are debilitating diseases with overlapping symptomology and there are currently no validated tests for definitive diagnosis of either syndrome. While there is evidence supporting the premise that some herpesviruses may act as possible triggers of ME/CFS, the involvement of herpesviruses in the pathophysiology of GWI has not been studied in spite of a higher prevalence of ME/CFS in these patients. We have previously demonstrated that the deoxyuridine triphosphate nucleotidohydrolases (dUTPase) encoded by Epstein-Barr virus (EBV), human herpesvirus-6 (HHV-6), and varicella-zoster virus (VZV) possess novel functions in innate and adaptive immunity. The results of this study demonstrate that a significant percentage of patients with ME/CFS (30.91-52.7%) and GWI (29.34%) are simultaneously producing antibodies against multiple human herpesviruses-encoded dUTPases and/or the human dUTPase when compared to controls (17.21%). GWI patients exhibited significantly higher levels of antibodies to the HHV-6 and human dUTPases than controls (P = 0.0053 and P = 0.0036, respectively), while the ME/CFS cohort had higher anti-EBV-dUTPase antibodies than in both GWI patients (P = 0.0008) and controls (P < 0.0001) as well as significantly higher anti-human dUTPase antibodies than in controls (P = 0.0241). These results suggest that screening of patients' sera for the presence of various combinations of anti-dUTPase antibodies could be used as potential biomarkers to help identify/distinguish patients with these syndromes and better direct treatment.

Promoting children's learning and development in conflict-affected countries: Testing change process in the Democratic Republic of the Congo.

Improving children's learning and development in conflict-affected countries is critically important for breaking the intergenerational transmission of violence and poverty. Yet there is currently a stunning lack of rigorous evidence as to whether and how programs to improve learning and development in conflict-affected countries actually work to bolster children's academic learning and socioemotional development. This study tests a theory of change derived from the fields of developmental psychopathology and social ecology about how a school-based universal socioemotional learning program, the International Rescue Committee's Learning to Read in a Healing Classroom (LRHC), impacts children's learning and development. The study was implemented in three conflict-affected provinces of the Democratic Republic of the Congo and employed a cluster-randomized waitlist control design to estimate impact. Using multilevel structural equation modeling techniques, we found support for the central pathways in the LRHC theory of change. Specifically, we found that LRHC differentially impacted dimensions of the quality of the school and classroom environment at the end of the first year of the intervention, and that in turn these dimensions of quality were differentially associated with child academic and socioemotional outcomes. Future implications and directions are discussed.

Deriving gradient measures of child speech from crowdsourced ratings.

Recent research has demonstrated that perceptual ratings aggregated across multiple non-expert listeners can reveal gradient degrees of contrast between sounds that listeners might transcribe identically. Aggregated ratings have been found to correlate strongly with acoustic gold standard measures both when individual raters use a continuous rating scale such as visual analog scaling (Munson et al., 2012) and when individual raters provide binary ratings (McAllister Byun, Halpin, & Szeredi, 2015). In light of evidence that inexperienced listeners use continuous scales less consistently than experienced listeners, this study investigated the relative merits of binary versus continuous rating scales when aggregating responses over large numbers of naive listeners recruited through online crowdsourcing. Stimuli were words produced by children in treatment for misarticulation of North American English /r/. Each listener rated the same 40 tokens two times: once using Visual Analog Scaling (VAS) and once using a binary rating scale. The gradient rhoticity of each item was then estimated using (a) VAS click location, averaged across raters; (b) the proportion of raters who assigned the "correct /r/" label to each item in the binary rating task (pˆ). First, we validate these two measures of rhoticity against each other and against an acoustic gold standard. Second, we explore the range of variability in individual response patterns that underlie these group-level data. Third, we integrate statistical, theoretical, and practical considerations to offer guidelines for determining which measure to use in a given situation.

Direction of attentional focus in biofeedback treatment for /r/ misarticulation.

BACKGROUND: Maintaining an external direction of focus during practice is reported to facilitate acquisition of non-speech motor skills, but it is not known whether these findings also apply to treatment for speech errors. This question has particular relevance for treatment incorporating visual biofeedback, where clinician cueing can direct the learner's attention either internally (i.e., to the movements of the articulators) or externally (i.e., to the visual biofeedback display). AIMS: This study addressed two objectives. First, it aimed to use single-subject experimental methods to collect additional evidence regarding the efficacy of visual-acoustic biofeedback treatment for children with /r/ misarticulation. Second, it compared the efficacy of this biofeedback intervention under two cueing conditions. In the external focus (EF) condition, participants' attention was directed exclusively to the external biofeedback display. In the internal focus (IF) condition, participants viewed a biofeedback display, but they also received articulatory cues encouraging an internal direction of attentional focus. METHODS & PROCEDURES: Nine school-aged children were pseudo-randomly assigned to receive either IF or EF cues during 8 weeks of visual-acoustic biofeedback intervention. Accuracy in /r/ production at the word level was probed in three to five pre-treatment baseline sessions and in three post-treatment maintenance sessions. Outcomes were assessed using visual inspection and calculation of effect sizes for individual treatment trajectories. In addition, a mixed logistic model was used to examine across-subjects effects including phase (pre/post-treatment), /r/ variant (treated/untreated), and focus cue condition (internal/external). OUTCOMES & RESULTS: Six out of nine participants showed sustained improvement on at least one treated /r/ variant; these six participants were evenly divided across EF and IF treatment groups. Regression results indicated that /r/ productions were significantly more likely to be rated accurate post- than pre-treatment. Internal versus external direction of focus cues was not a significant predictor of accuracy, nor did it interact significantly with other predictors. CONCLUSIONS: The results are consistent with previous literature reporting that visual-acoustic biofeedback can produce measurable treatment gains in children who have not responded to previous intervention. These findings are also in keeping with previous research suggesting that biofeedback may be sufficient to establish an external attentional focus, independent of verbal cues provided. The finding that explicit articulator placement cues were not necessary for progress in treatment has implications for intervention practices for speech-sound disorders in children.

Targeted Integration of Single-Copy Transgenes in Drosophila melanogaster Tissue-Culture Cells Using Recombination-Mediated Cassette Exchange.

Transfection of transgenes into Drosophila cultured cells is a standard approach for studying gene function. However, the number of transgenes present in the cell following transient transfection or stable random integration varies, and the resulting differences in expression level affect interpretation. Here we developed a system for Drosophila cell lines that allows selection of cells with a single-copy transgene inserted at a specific genomic site using recombination-mediated cassette exchange (RMCE). We used the φC31 integrase and its target sites attP and attB for RMCE. Cell lines with an attP-flanked genomic cassette were transfected with donor plasmids containing a transgene of interest (UAS-x), a dihydrofolate reductase (UAS-DHFR) gene flanked by attB sequences, and a thymidine kinase (UAS-TK) gene in the plasmid backbone outside the attB sequences. In cells undergoing RMCE, UAS-x and UAS-DHFR were exchanged for the attP-flanked genomic cassette, and UAS-TK was excluded. These cells were selected using methotrexate, which requires DHFR expression, and ganciclovir, which causes death in cells expressing TK. Pure populations of cells with one copy of a stably integrated transgene were efficiently selected by cloning or mass culture in ∼6 weeks. Our results show that RMCE avoids the problems associated with current methods, where transgene number is not controlled, and facilitates the rapid generation of Drosophila cell lines in which expression from a single transgene can be studied.

Online crowdsourcing for efficient rating of speech: a validation study.

UNLABELLED: Blinded listener ratings are essential for valid assessment of interventions for speech disorders, but collecting these ratings can be time-intensive and costly. This study evaluated the validity of speech ratings obtained through online crowdsourcing, a potentially more efficient approach. 100 words from children with /r/ misarticulation were electronically presented for binary rating by 35 phonetically trained listeners and 205 naïve listeners recruited through the Amazon Mechanical Turk (AMT) crowdsourcing platform. Bootstrapping was used to compare different-sized samples of AMT listeners against a "gold standard" (mode across all trained listeners) and an "industry standard" (mode across bootstrapped samples of three trained listeners). There was strong overall agreement between trained and AMT listeners. The "industry standard" level of performance was matched by bootstrapped samples with n = 9 AMT listeners. These results support the hypothesis that valid ratings of speech data can be obtained in an efficient manner through AMT. Researchers in communication disorders could benefit from increased awareness of this method. LEARNING OUTCOMES: Readers will be able to (a) discuss advantages and disadvantages of data collection through the crowdsourcing platform Amazon Mechanical Turk (AMT), (b) describe the results of a validity study comparing samples of AMT listeners versus phonetically trained listeners in a speech-rating task.

Modelling dyadic interaction with Hawkes processes.

We apply the Hawkes process to the analysis of dyadic interaction. The Hawkes process is applicable to excitatory interactions, wherein the actions of each individual increase the probability of further actions in the near future. We consider the representation of the Hawkes process both as a conditional intensity function and as a cluster Poisson process. The former treats the probability of an action in continuous time via non-stationary distributions with arbitrarily long historical dependency, while the latter is conducive to maximum likelihood estimation using the EM algorithm. We first outline the interpretation of the Hawkes process in the dyadic context, and then illustrate its application with an example concerning email transactions in the work place.

Violence in the massage parlor industry: experiences of Canadian-born and immigrant women.

We examined and contrasted 129 Canadian-born and immigrant women's experiences of violence and associated structural and interpersonal factors within indoor commercial sex venues. The majority experienced at least one form of structural, interpersonal, or both types of violence, with the attempted removal of a condom during sexual services being cited most frequently. Canadian-born women reported more frequent violent assaults in the survey data. The women's qualitative narratives illustrated that perceptions of violence differed significantly among Canadian versus non-Canadian born women. Findings concerning racialization and gendered relations of power have important implications for prevention and interventions to support victims of abuse.

On the Relation Between the Linear Factor Model and the Latent Profile Model.

The relationship between linear factor models and latent profile models is addressed within the context of maximum likelihood estimation based on the joint distribution of the manifest variables. Although the two models are well known to imply equivalent covariance decompositions, in general they do not yield equivalent estimates of the unconditional covariances. In particular, a 2-class latent profile model with Gaussian components underestimates the observed covariances but not the variances, when the data are consistent with a unidimensional Gaussian factor model. In explanation of this phenomenon we provide some results relating the unconditional covariances to the goodness of fit of the latent profile model, and to its excess multivariate kurtosis. The analysis also leads to some useful parameter restrictions related to symmetry.

Adolescent smoking: effect of school and community characteristics.

BACKGROUND: A substantial challenge in addressing adolescent tobacco use is that smoking behaviors occur in complex environments that involve the school setting and larger community context. PURPOSE: This study provides an integrated description of factors from the school and community environment that affect youth smoking and explains variation in individual smoking behaviors both within and across schools/communities. METHODS: Data were collected from 82 randomly sampled secondary schools in five Canadian provinces (British Columbia, Manitoba, Ontario, Quebec, Newfoundland, and Labrador) during the 2003-2004 school year. Cross-sectional data were obtained from students; school administrators (school-based tobacco control policies and programs); and from observations in the community. In 2009, hierarchic logistic regression was used to model the role of individual, school, and community variables in predicting student smoking outcomes. RESULTS: Students who attended a school with a focus on tobacco prevention (OR=0.87, 95% CI=0.81, 0.94) and stronger policies prohibiting tobacco use (OR=0.92, 95% CI=0.88, 0.97) were less likely to smoke than students who attended a school without these characteristics. A student was more likely to smoke if a greater number of students smoked on the school periphery (OR=1.25, 95% CI=1.07, 1.47). Within the community, price per cigarette (OR=0.91, 95% CI=0.84, 0.99) and immigrants (OR=0.99, 95% CI=0.98, 0.99) were inversely related to students' smoking status. CONCLUSIONS: The results suggest that school and community characteristics account for variation in smoking levels across schools. Based on the current findings, the ideal school setting that supports low student smoking levels is located in a neighborhood where the cost of cigarettes is high, provides tobacco prevention education, and has a policy prohibiting smoking.

The influence of school policies on smoking prevalence among students in grades 5-9, Canada, 2004-2005.

INTRODUCTION: School characteristics may account for some of the variation in smoking prevalence among schools. The purpose of this study was to investigate the relationships between characteristics of school tobacco policies and school smoking prevalence. We also examined the relationship between these characteristics and individual smoking status. METHODS: Tobacco policy data were collected from schools in 10 Canadian provinces during the 2004-2005 school year. Written tobacco policies were collected from each school to examine policy intent, and school administrators were surveyed to assess policy enforcement. Students in grades 5 through 9 completed the Youth Smoking Survey to assess smoking behaviors and attitudes. We used negative binomial regression and multilevel logistic regression to predict the influence of school policies on smoking behavior at the school and student levels. RESULTS: School policies that explicitly stated purpose and goals predicted lower prevalence of smoking at the school and individual levels. Policies that prohibited smoking on school grounds at all times predicted lower smoking prevalence at the school level but not at the individual level. CONCLUSION: For maximum effectiveness, school smoking policies should clearly state a purpose and goals and should emphasize smoking prohibition. These policies can help reduce smoking prevalence among youths and are part of a comprehensive school approach to tobacco control.