Comparación de la eficiencia en la estimación de parámetros entre análisis de estructura de covarianzas, modelo de rutas mediante mínimos cuadrados parciales y análisis generalizado de componentes estructurales: un estudio de simulación

Tesis doctoral inédita, leída en la Universidad Autónoma de Madrid, Facultad de Psicología. Departamento de Psicología Social y Metodología. Fecha de lectura: 20 de noviembre de 201

Accuracy on parameter recovery, with ordinals data, of structure covariance analysis and partial least squares path modeling

ReconocimientoSe compara la precisión en la recuperación de parámetros del Análisis de Estructura de Covarianza (ACOV) y el Modelo de Rutas mediante Mínimos Cuadrados Parciales (PLS-PM), en un modelo simple con variables manifiestas simuladas con escala ordinal de cinco puntos. Se utiliza un diseño experimental, manipulando el método de estimación, tamaño muestral, nivel de asimetría y tipo de especificación del modelo. Se valora la media de las diferencias absolutas para el modelo estructural. ACOV presenta estimaciones más precisas que PLS-PM, en distintas condiciones experimentales. Cuando se utiliza un tamaño muestral pequeño, ambas técnicas son igualmente precisas. Se sugiere utilizar ACOV frente a PLS-PM. Se desaconseja fundamentar la elección de PLS-PM frente a ACOV en la utilización de una muestra pequeñaThe accuracy on parameter recovery is compared between Structure Covariance Analysis (ACOV) and Partial Least Squares Path Modeling (PLS-PM), with simulated ordinals data with 5 points, in a simple model. An experimental design is used, controlling the estimation method, sample size, skewness level and model specification. Mean absolute differences are used to assess accuracy for the structural model. ACOV provided more accurate estimates of the structural parameters than PLS-PM in different experimental conditions. With a small sample size, both techniques are equally accurate. Using ACOV against PLS-PM is suggested. PLS choosing ACOV instead based on the use of a small sample size is not recommendedArtículo de investigación. FONDECYT de Iniciación 2013, N° 11130722. Beca Presidente de la República de Chile (2008), de la Comisión Nacional de Investigación Científica y Tecnológica de Chile (CONICYT

Shared book-Reading in early childhood education: Teachers’ mediation in children’s communicative development

Fostering communicative skills in young children is essential for their holistic development. Book-reading activities have been shown to be a valuable tool for supporting communicative exchanges between children and adults, but there is limited research on actual educational practices with children under 3 years old. This experimental study explores teaching practices in Chilean early childhood education with children from 4 to 17 months of age. We focused on children’s performance of diverse communicative signs, as well as on the effect of the teacher’s mediation (signs and strategies) in a triadic shared-reading interaction (teacher-child-book). The study is part of a larger cross-sectional project. We conducted an experimental study following a pre-test–post-test design with 11 children, who were randomly assigned to either the control or the experimental group. In addition, we conducted a 6-week intervention on shared book reading between the pre- and post-test stages. We observed that children used a wide range of communicative signs when engaging in shared interactions with their teacher and different books. In the experimental group, children performed more communicative signs after participating in the intervention than at the beginning of the study. The reading experience that they gained through the intervention could also explain the larger proportion of uses of the books, as compared to their control counterparts. Additionally, children performed different combinations of vocalizations, words, or repetitions within a single use. The conventional use of a book is not evident for an infant, and as such it requires the systematic and semiotically mediated action of an adult to be consolidated. We conclude that offering preschool teachers a diverse selection of books enables them to better adjust to the particularities of each child. In this scenario educators are able to promote efficient spaces for children’s participation, increasing the complexity and variety of their communicative repertoireThis study was funded by the ChileanNational Fund for Scientific and Technological Development (Fondo Nacional de Desarrollo Científico y Tecnológico, FONDECYT/CONICYT/ANID) under the “Fondecyt de iniciación 11170804” (Initiation Research) Funding Programm

Getting away from the point: The emergence of ostensive gestures and their functions

Within developmental psychology, pointing gestures have received a great deal of attention, while ostensive gestures have been overlooked in terms of their emergence and intentionality. In a longitudinal and micro-genetic study with six children at 9, 11, and 13 months of age, we codified gesture production of children within second-by-second data frames. We identified 480 instances of gestures and categorised whether they were of ostensive, ostensive-indexical, or indexical nature. We specified the communicative function of each gesture by analysing the object involved and their circumstances of production. Data analysis include frequencies, binomial tests, proportion comparisons, and repeated measures ANOVA. We identified a phatic function in other-directed gestures, as well as exploratory and private functions in selfdirected gestures. This has important implications for children development since ostensive gestures are easier to produce and to understand than pointing. The consideration of objects would be essential for defining the communicative function of gesturesThis study was supported by the program for the Training of University Teachers (Formación de Profesorado Universitario – FPU) of the Spanish Ministry of Education granted to the first author [reference AP2009-4064

Influence of Family Involvement and Children’s Socioemotional Development on the Learning Outcomes of Chilean Students

There is an extensive body of evidence to support both family involvement and students’ socioemotional development as key factors in the promotion of learning outcomes. However, there is insufficient evidence to establish exactly what this impact is when both factors are considered simultaneously. Therefore, the aim of this study is to analyze the influence of family involvement and socioemotional development on learning outcomes of Chilean students, identifying the structure that most correctly identifies the influence of the predictor variables (family involvement and socioemotional development) on learning outcomes. We present the following three hypotheses that consider possible basic interrelation structures: (1) The influence of family involvement on learning outcomes is mediated by students’ socioemotional development (mediation hypothesis); (2) The influence of family involvement on learning outcomes is moderated by students’ socioemotional development (moderation hypothesis); (3) Family involvement and students’ socio emotional development directly affect learning outcomes (covariance hypothesis). The structures were evaluated by means of a structural equation model analysis. The study included 768 students who attended second and third elementary grades in Chilean schools. The children were between 7 and 11 years old (M = 8.29, SD = 0.86); 41.3% were girls and 58.7% were boys. The results show that family involvement and students’ emotional development directly affect learning outcomes (CFI = 0.995, TLI = 0.993, RMSEA = 0.016). From the results, we can conclude that the data support the hypothesis that both family involvement and socioemotional development are predictors of learning outcomes, thereby rejecting that the impact of family involvement on learning outcomes is mediated or moderated by socioemotional development

Precisión en la recuperación de parámetros, con datos ordinales, en el Análisis de Estructura de Covarianza y el Modelo de Rutas mediante Mínimos Cuadrados Parciales

The accuracy on parameter recovery is compared between Structure Covariance Analysis (ACOV) and Partial Least Squares Path Modeling (PLS-PM), with simulated ordinals data with 5 points, in a simple model. An experimental design is used, controlling the estimation method, sample size, skewness level and model specification. Mean absolute differences are used to assess accuracy for the structural model. ACOV provided more accurate estimates of the structural parameters than PLS-PM in different experimental conditions. With a small sample size, both techniques are equally accurate. Using ACOV against PLS-PM is suggested. PLS choosing ACOV instead based on the use of a small sample size is not recommended.Se compara la precisión en la recuperación de parámetros del Análisis de Estructura de Covarianza (ACOV) y el Modelo de Rutas mediante Mínimos Cuadrados Parciales (PLS-PM), en un modelo simple con variables manifiestas simuladas con escala ordinal de cinco puntos. Se utiliza un diseño experimental, manipulando el método de estimación, tamaño muestral, nivel de asimetría y tipo de especificación del modelo. Se valora la media de las diferencias absolutas para el modelo estructural. ACOV presenta estimaciones más precisas que PLS-PM, en distintas condiciones experimentales. Cuando se utiliza un tamaño muestral pequeño, ambas técnicas son igualmente precisas. Se sugiere utilizar ACOV frente a PLS-PM. Se desaconseja fundamentar la elección de PLS-PM frente a ACOV en la utilización de una muestra pequeña

Precisión en la recuperación de parámetros, con datos ordinales, en el Análisis de Estructura de Covarianza y el Modelo de Rutas mediante Mínimos Cuadrados Parciales

The accuracy on parameter recovery is compared between Structure Covariance Analysis (ACOV) and Partial Least Squares Path Modeling (PLS-PM), with simulated ordinals data with 5 points, in a simple model. An experimental design is used, controlling the estimation method, sample size, skewness level and model specification. Mean absolute differences are used to assess accuracy for the structural model. ACOV provided more accurate estimates of the structural parameters than PLS-PM in different experimental conditions. With a small sample size, both techniques are equally accurate. Using ACOV against PLS-PM is suggested. PLS choosing ACOV instead based on the use of a small sample size is not recommended.Se compara la precisión en la recuperación de parámetros del Análisis de Estructura de Covarianza (ACOV) y el Modelo de Rutas mediante Mínimos Cuadrados Parciales (PLS-PM), en un modelo simple con variables manifiestas simuladas con escala ordinal de cinco puntos. Se utiliza un diseño experimental, manipulando el método de estimación, tamaño muestral, nivel de asimetría y tipo de especificación del modelo. Se valora la media de las diferencias absolutas para el modelo estructural. ACOV presenta estimaciones más precisas que PLS-PM, en distintas condiciones experimentales. Cuando se utiliza un tamaño muestral pequeño, ambas técnicas son igualmente precisas. Se sugiere utilizar ACOV frente a PLS-PM. Se desaconseja fundamentar la elección de PLS-PM frente a ACOV en la utilización de una muestra pequeña

Libro de Proyectos Finales 2021 primer semestre

PregradoIngeniero CivilIngeniero de SistemasIngeniero ElectricistaIngeniero ElectrónicoIngeniero IndustrialIngeniero Mecánic

Immunoglobulin, glucocorticoid, or combination therapy for multisystem inflammatory syndrome in children: a propensity-weighted cohort study

Background: Multisystem inflammatory syndrome in children (MIS-C), a hyperinflammatory condition associated with SARS-CoV-2 infection, has emerged as a serious illness in children worldwide. Immunoglobulin or glucocorticoids, or both, are currently recommended treatments. Methods: The Best Available Treatment Study evaluated immunomodulatory treatments for MIS-C in an international observational cohort. Analysis of the first 614 patients was previously reported. In this propensity-weighted cohort study, clinical and outcome data from children with suspected or proven MIS-C were collected onto a web-based Research Electronic Data Capture database. After excluding neonates and incomplete or duplicate records, inverse probability weighting was used to compare primary treatments with intravenous immunoglobulin, intravenous immunoglobulin plus glucocorticoids, or glucocorticoids alone, using intravenous immunoglobulin as the reference treatment. Primary outcomes were a composite of inotropic or ventilator support from the second day after treatment initiation, or death, and time to improvement on an ordinal clinical severity scale. Secondary outcomes included treatment escalation, clinical deterioration, fever, and coronary artery aneurysm occurrence and resolution. This study is registered with the ISRCTN registry, ISRCTN69546370. Findings: We enrolled 2101 children (aged 0 months to 19 years) with clinically diagnosed MIS-C from 39 countries between June 14, 2020, and April 25, 2022, and, following exclusions, 2009 patients were included for analysis (median age 8·0 years [IQR 4·2–11·4], 1191 [59·3%] male and 818 [40·7%] female, and 825 [41·1%] White). 680 (33·8%) patients received primary treatment with intravenous immunoglobulin, 698 (34·7%) with intravenous immunoglobulin plus glucocorticoids, 487 (24·2%) with glucocorticoids alone; 59 (2·9%) patients received other combinations, including biologicals, and 85 (4·2%) patients received no immunomodulators. There were no significant differences between treatments for primary outcomes for the 1586 patients with complete baseline and outcome data that were considered for primary analysis. Adjusted odds ratios for ventilation, inotropic support, or death were 1·09 (95% CI 0·75–1·58; corrected p value=1·00) for intravenous immunoglobulin plus glucocorticoids and 0·93 (0·58–1·47; corrected p value=1·00) for glucocorticoids alone, versus intravenous immunoglobulin alone. Adjusted average hazard ratios for time to improvement were 1·04 (95% CI 0·91–1·20; corrected p value=1·00) for intravenous immunoglobulin plus glucocorticoids, and 0·84 (0·70–1·00; corrected p value=0·22) for glucocorticoids alone, versus intravenous immunoglobulin alone. Treatment escalation was less frequent for intravenous immunoglobulin plus glucocorticoids (OR 0·15 [95% CI 0·11–0·20]; p<0·0001) and glucocorticoids alone (0·68 [0·50–0·93]; p=0·014) versus intravenous immunoglobulin alone. Persistent fever (from day 2 onward) was less common with intravenous immunoglobulin plus glucocorticoids compared with either intravenous immunoglobulin alone (OR 0·50 [95% CI 0·38–0·67]; p<0·0001) or glucocorticoids alone (0·63 [0·45–0·88]; p=0·0058). Coronary artery aneurysm occurrence and resolution did not differ significantly between treatment groups. Interpretation: Recovery rates, including occurrence and resolution of coronary artery aneurysms, were similar for primary treatment with intravenous immunoglobulin when compared to glucocorticoids or intravenous immunoglobulin plus glucocorticoids. Initial treatment with glucocorticoids appears to be a safe alternative to immunoglobulin or combined therapy, and might be advantageous in view of the cost and limited availability of intravenous immunoglobulin in many countries. Funding: Imperial College London, the European Union's Horizon 2020, Wellcome Trust, the Medical Research Foundation, UK National Institute for Health and Care Research, and National Institutes of Health