Search results for "variance"
showing 10 items of 2030 documents
Family related variables effect on later educational outcome: a further geospatial analysis on TIMSS 2015 Finland
2020
AbstractFamily-related factors, like parent’s educational level, their values and expectations have a significant impact on child’s early skills and later educational outcomes. Further, parents provide their child, alongside with other learning environments, a broad mathematical and early literacy input. This study investigates the relationship between family-related socio-economic and other factors like, parental education, amount of books at home, parental attitudes towards mathematics and science, parental perception of child’s early skills and student’s later academic achievement. This is studied in the light of the Finnish data collected for Trends in International Mathematics and Scie…
Verbal counting skill predicts later math performance and difficulties in middle school
2019
This study examined the role of verbal counting skill as an early predictor of math performance and difficulties (at or below −1.5 standard deviation in basic math skills) in middle school. The role of fourth-grade level arithmetical skills (i.e., calculation fluency, multi-digit arithmetic i.e. procedural calculation, and word problem solving) as mediators was also investigated. The participants included 207 children in central Finland who were studied from kindergarten to the seventh grade. Path modeling showed that verbal counting in kindergarten is a strong predictor for basic math performance in seventh grade, explaining even 52% of the variance in these skills after controlling for th…
The variance of the ℓnp-norm of the Gaussian vector, and Dvoretzky's theorem
2018
Let n be a large integer, and let G be the standard Gaussian vector in Rn. Paouris, Valettas and Zinn (2015) showed that for all p∈[1,clogn], the variance of the ℓnp-norm of G is equivalent, up to a constant multiple, to 2ppn2/p−1, and for p∈[Clogn,∞], to (logn)−1. Here, C,c>0 are universal constants. That result left open the question of estimating the variance for p logarithmic in n. In this paper, the question is resolved by providing a complete characterization of Var∥G∥p for all p. It is shown that there exist two transition points (windows) in which the behavior of Var∥G∥p changes significantly. Some implications of the results are discussed in the context of random Dvoretzky's theore…
Estrés percibido y felicidad auténtica a través del nivel de actividad física en jóvenes universitarios
2020
Se ha demostrado en la literatura que el estrés y la felicidad se han relacionado de diversas maneras, y estas a su vez, también se relacionan con la práctica de actividad física (AF). El objetivo de este trabajo fue poner a prueba el papel de la AF en la reducción del estrés y el aumento de la felicidad, así como su rol mediador en la relación entre ambas variables. Concretamente, se pusieron a prueba las siguientes hipótesis: 1) la percepción del estrés (con o sin control de la situación estresante) y la felicidad auténtica difieren en función del nivel de AF; 2) a mayor práctica de AF, mayor percepción de control en la situación estresante y menor percepción de sentirse sobrepasado por l…
Attitudes and related perceptions about product placement: a comparison of Finland, Italy and the United States
2015
The primary goal of our study is to explore cross-national differences in attitudes and perceptions about product placements, after investigating measurement invariance. Our cross-national focus includes three countries that have not been compared previously: Finland, Italy and the USA, which differ significantly in terms of the evolution/maturity of product placement markets, regulatory structures and cultural contexts. Motivated by earlier studies, we investigate the cross-national measurement invariance of scales to measure four research constructs related to the product placement domain (attitude toward credibility of advertising, attitude toward advertising-in-general, attitude toward …
Ensuring the comparability of cross-national survey data on intimate partner violence against women: a cross-sectional, population-based study in the…
2020
Objectives To ensure the cross-national comparability of the set of questions addressing physical and sexual intimate partner violence against women (IPVAW) included in the European Union (EU) Agency for Fundamental Rights (FRA) survey. Once the measurement invariance of these measures is established, we aim to make appropriate and valid comparisons of the levels of physical and sexual IPVAW across the EU countries. Design Cross-sectional, population-based study. Participants Data were drawn from the survey conducted by the FRA on violence against women, including the responses of 42 002 adult women from the 28 countries of the EU. Main outcome measures The set of questions addressing lifet…
An ultra-short measure of positive and negative affect: The Reduced Affective Well-Being Scale (RAWS).
2020
In applied organizational research, where economy of scale is often a crucial factor in successful assessment, ultra-short measures are often needed. This study investigates the psychometric properties of the Reduced Affective Well-Being Scale (RAWS), an ultra-short measure of positive and negative affect in the workplace. This 6-item ultra-short version was compared with the original 12-item scale proposed by Segura and González-Romá (2003) in terms of internal consistency and criterion validity, using a sample of 1117 bank employees. In addition, longitudinal measurement invariance and within-subject reliability of the RAWS over time were assessed in a longitudinal sample of 458 employees…
Kernel Feature Extraction Methods for Remote Sensing Data Analysis
2014
Technological advances in the last decades have improved our capabilities of collecting and storing high data volumes. However, this makes that in some fields, such as remote sensing several problems are generated in the data processing due to the peculiar characteristics of their data. High data volume, high dimensionality, heterogeneity and their nonlinearity, make that the analysis and extraction of relevant information from these images could be a bottleneck for many real applications. The research applying image processing and machine learning techniques along with feature extraction, allows the reduction of the data dimensionality while keeps the maximum information. Therefore, develo…
Robustifying principal component analysis with spatial sign vectors
2012
In this paper, we apply orthogonally equivariant spatial sign covariance matrices as well as their affine equivariant counterparts in principal component analysis. The influence functions and asymptotic covariance matrices of eigenvectors based on robust covariance estimators are derived in order to compare the robustness and efficiency properties. We show in particular that the estimators that use pairwise differences of the observed data have very good efficiency properties, providing practical robust alternatives to classical sample covariance matrix based methods. peerReviewed