Search results for " Sampling"
showing 10 items of 375 documents
Statistical inference and Monte Carlo algorithms
1996
This review article looks at a small part of the picture of the interrelationship between statistical theory and computational algorithms, especially the Gibbs sampler and the Accept-Reject algorithm. We pay particular attention to how the methodologies affect and complement each other.
The Critical Role of Morale in Ukraine’s Fight against the Russian Invasion
2020
The role of morale, also known as esprit de corps, in a high technology environment of the 21st century warfare, is poorly understood. The purpose of the study is to seek evidence for the proposition that the Ukraine’s population and military forces morale has neutralized the asymmetric difference in the military force of the two countries. The academic and practical implications have the potential to refocus military practice. An exploratory qualitative research method using theoretical sampling was used in this study. The study finds significant evidence for high morale as a balancing factor in the asymmetric differences of Russia and Ukraine, which explains Ukraine’s success against grea…
Heretical Mutiple Importance Sampling
2016
Multiple Importance Sampling (MIS) methods approximate moments of complicated distributions by drawing samples from a set of proposal distributions. Several ways to compute the importance weights assigned to each sample have been recently proposed, with the so-called deterministic mixture (DM) weights providing the best performance in terms of variance, at the expense of an increase in the computational cost. A recent work has shown that it is possible to achieve a trade-off between variance reduction and computational effort by performing an a priori random clustering of the proposals (partial DM algorithm). In this paper, we propose a novel "heretical" MIS framework, where the clustering …
Analysis of Educational Frequency Data from a Complex Sample Survey
1991
Abstract Some recent methods are presented for analyzing categorial data from complex surveys involving clustering familiar in educational research where e.g. teaching groups are used as sample clusters. The methods are introduced through a discussion of the test of independence on a two‐way table and the analysis of a two‐way table using logistic regression models. The analyses are illustrated using data from the First National Assessment of the Finnish Comprehensive School 1979. The primary focus of the paper is on the methods that provide first‐order corrections to standard multinomial‐based chi‐square tests by taking account of survey design effects. Both first‐ and second‐order correct…
Selection of Large Sub-Samples from the Continuous Sample of Working Lives Representative of the Benefits Provided by the Spanish Public Pension Syst…
2016
The Continuous Sample of Working Lives (CSWL) is a set of anonymized microdata with information about individuals taken from Spanish Social Security records. It provides very valuable information, which is used in many studies on labor economics and in the analysis of the Spanish public pension system. This article presents two major contributions: The first is an analysis of how representative CSWL is of the population of pensioners for the period 2005-2013. It is concluded that the CSWL does not follow the same distribution as the population with respect to some types of benefits, and that this happens in most waves. One of the reasons is that it is obtained by simple random sampling, so …
Emotional and behavioral difficulties in adolescence: Relationship with emotional well-being, affect, and academic performance
2018
Abstract The main purpose of this study was to examine difficulties in behavioral and emotional adjustment and their relationship to subjective well-being, positive and negative affect, and academic performance in a representative sample of nonclinical adolescents. The sample consisted of a total of 1,664 participants (M = 16.12 years, SD = 1.36, range 14-19 years), selected through stratified cluster sampling. The instruments used were the Strengths and Difficulties Questionnaire (SDQ), the Positive and Negative Affect Schedule for Children (PANAS-C), the Personal Wellbeing Index-School Children (PWI-SC), the ad hoc academic performance questionnaire, and the Oviedo Scale of Response Infre…
Sampling Design in SHARE Wave 8 and Recruitment of Refreshment Samples until the Suspension of Fieldwork
2022
The aim of the SHARE survey design is to be able to draw inferences about the population of people aged 50 years or older across countries by using probability-based sampling. This chapter documents the sampling design adopted in the eighth wave of SHARE that had to be suspended due to COVID-19 in March 2020. Starting with a definition of the SHARE target population, we describe the protocol for harmonizing and documenting the sampling procedure and present the sampling frames used by the countries that recruited a baseline or refreshment sample in Wave 8. We then discuss some important aspects of the SHARE sampling designs, such as stratification, clustering, variation in selection probabi…
The uncertainties of climate change in Spanish daily newspapers: Content analysis of press coverage from 2000 to 2010
2014
This paper explores media coverage of climate science through a selection of Spanish newspapers (El País, El Mundo, ABC, Expansión and Levante). We selected a stratified random sample of 363 items to be studied for eleven years (2000-2010). Content analysis allowed us to find out media attention paid to climate science, prevalence of informative tables, evaluation and characterization of news, as well as the presence of questioning or rejection of climate change. According to main results, press coverage of climate science in Spain was mainly focused on the consequences rather than on the causes or natural sources, and media attention paid to it was limited. Overlapping with social and macr…
Il disegno della ricerca
2008
Il capitolo metodologico illustra i metodi di campionamento utilizzati; gli strumenti di rilevazione dei dati e le tecniche di analisi utilizzati.
Conditional Bias Robust Estimation of the Total of Curve Data by Sampling in a Finite Population: An Illustration on Electricity Load Curves
2020
Abstract For marketing or power grid management purposes, many studies based on the analysis of total electricity consumption curves of groups of customers are now carried out by electricity companies. Aggregated totals or mean load curves are estimated using individual curves measured at fine time grid and collected according to some sampling design. Due to the skewness of the distribution of electricity consumptions, these samples often contain outlying curves which may have an important impact on the usual estimation procedures. We introduce several robust estimators of the total consumption curve which are not sensitive to such outlying curves. These estimators are based on the conditio…