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Sample allocation balancing overall representativeness and stratum precision.

Authors :
Diaz-Quijano, Fredi Alexander
Source :
Annals of Epidemiology. Aug2018, Vol. 28 Issue 8, p570-575. 6p.
Publication Year :
2018

Abstract

<bold>Purpose: </bold>In large-scale surveys, it is often necessary to distribute a preset sample size among a number of strata. Researchers must make a decision between prioritizing overall representativeness or precision of stratum estimates. Hence, I evaluated different sample allocation strategies based on stratum size.<bold>Methods: </bold>The strategies evaluated herein included allocation proportional to stratum population; equal sample for all strata; and proportional to the natural logarithm, cubic root, and square root of the stratum population. This study considered the fact that, from a preset sample size, the dispersion index of stratum sampling fractions is correlated with the population estimator error and the dispersion index of stratum-specific sampling errors would measure the inequality in precision distribution. Identification of a balanced and efficient strategy was based on comparing those both dispersion indices.<bold>Results: </bold>Balance and efficiency of the strategies changed depending on overall sample size. As the sample to be distributed increased, the most efficient allocation strategies were equal sample for each stratum; proportional to the logarithm, to the cubic root, to square root; and that proportional to the stratum population, respectively.<bold>Conclusions: </bold>Depending on sample size, each of the strategies evaluated could be considered in optimizing the sample to keep both overall representativeness and stratum-specific precision. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
10472797
Volume :
28
Issue :
8
Database :
Academic Search Index
Journal :
Annals of Epidemiology
Publication Type :
Academic Journal
Accession number :
130837906
Full Text :
https://doi.org/10.1016/j.annepidem.2018.04.011