Search results for "sampling design"

Latin hypercube sampling with inequality constraints

2010

International audience; In some studies requiring predictive and CPU-time consuming numerical models, the sampling design of the model input variables has to be chosen with caution. For this purpose, Latin hypercube sampling has a long history and has shown its robustness capabilities. In this paper we propose and discuss a new algorithm to build a Latin hypercube sample (LHS) taking into account inequality constraints between the sampled variables. This technique, called constrained Latin hypercube sampling (cLHS), consists in doing permutations on an initial LHS to honor the desired monotonic constraints. The relevance of this approach is shown on a real example concerning the numerical w…

Population size estimation of larval coregonids in large lakes: Stratified sampling design with a simple prediction model for vertical distribution

2009

Abstract The lake-specific vertical distribution of larval coregonids was assessed annually in Finnish lakes by bongo net sampling. The effect of inter-annual and inter-lake variation in vertical distributions on population estimates of larval coregonids were analysed in 1999–2008. The vertical distribution of newly hatched vendace ( Coregonus albula (L.)) and European whitefish ( Coregonus lavaretus L. s.l.) larvae was analysed and high inter-annual and lake-specific variation in the larval vertical distribution was found. Generally, in both littoral and pelagic areas, larvae were aggregated near the water surface, mostly in the top 30 cm layer. We compared observed and predicted density e…

Sampling design and weighting strategies in SHARE Wave 6

2017

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 …

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…

Sample design and weighting strategies in SHARE Wave 5

2015

This chapter provides a description of the sampling design and weighting strategies adopted in the fifth wave of SHARE. We begin by defining the target population that SHARE aims to represent. Next, we describe the sampling design focusing on the basic principles guiding the construction of the SHARE sample, the role played by sampling frames for coverage of the target population, and other important aspects of sampling - such as stratification, clustering and variation in selection probabilities - that affect the efficiency of sample-based inference. The chapter concludes with a description of the weighting strategies adopted by SHARE to handle problems of unit nonresponse in the baseline …

A theoretical and methodological framework for the analysis and measurement of environmental heritage at local level

2017

Abstract The study aims to assess the lived experience and the environmental heritage perceived level by residents of an high complexity rural area, and which is, in this context, the role played by production of renewable energies. The paper introduces the concept of rural capital as an effective tool for environmental heritage analysis and measurement. The proposed theoretical and methodological approach allows, in fact, its analysis in order to understand what dimensions related to territoriality are connected to the perceived level of environmental heritage at local level. Translated into operational terms, the methodology has resulted in an empirical analysis of a rural and inner area …

Statistical modelling and RCS detrending methods provide similar estimates of long-term trend in radial growth of common beech in north-eastern France

2011

International audience; Dendrochronological methods have greatly contributed to the documentation of past long-term trends in forest growth. These methods primarily focus on the high-frequency signals of tree ring chronologies. They require the removal of the ageing trend in tree growth, known as 'standardisation' or 'detrending', as a prerequisite to the estimation of such trends. Because the approach is sequential, it may however absorb part of the low-frequency historical signal. In this study, we investigate the effect of a sequential and a simultaneous estimation of the ageing trend on the chronology of growth. We formerly developed a method to estimate historical changes in growth, in…

Register data in sample allocations for small-area estimation

2018

The inadequate control of sample sizes in surveys using stratified sampling and area estimation may occur when the overall sample size is small or auxiliary information is insufficiently used. Very small sample sizes are possible for some areas. The proposed allocation based on multi-objective optimization uses a small-area model and estimation method and semi-collected empirical data annually collected empirical data. The assessment of its performance at the area and at the population levels is based on design-based sample simulations. Five previously developed allocations serve as references. The model-based estimator is more accurate than the design-based Horvitz–Thompson estimator and t…