Nature

Using exposure biomarkers in children to compare between-child and within-child variance and calculate correlations among siblings for multiple environmental chemicals

Longitudinal measurements of biomarkers for metals, phthalates, environmental tobacco smoke, organochlorine and organophosphate pesticides, polychlorinated biphenyls, and volatile organic compounds ...
JSTOR Daily

On Variance Estimation With Imputed Survey Data

Unit nonresponse and item nonresponse both occur frequently in surveys. Unit nonresponse is customarily handled by weighting adjustment, whereas item nonresponse is usually treated by some form of ...
Investopedia

Simple Random Sampling: 6 Basic Steps With Examples

Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...
Investopedia

Understanding Simple Random Sampling: Key Advantages and Limitations

Melissa Horton is a financial literacy professional. She has 10+ years of experience in the financial services and planning industry. Robert Kelly is managing director of XTS Energy LLC, and has more ...
National Academies of Sciences%2c Engineering%2c and Medicine

Estimating Water Use in the United States: A New Paradigm for the National Water-Use Information Program

Several states with extensive water use databases rely upon the census approach. That is, data are collected for all water users withdrawing amounts greater than a specified threshold that varies from ...