One possible explanation for the variability in estimates across the different nonprobability samples is the range of methods that online sample vendors employ. They differ on recruitment, weighting ...

Discover how simple random sampling ensures accurate and unbiased population research, offering efficiency and fairness over ...

1. Distinguish between probability and non-probability sampling and discuss the advantages and disadvantages of each. If you can not specify the probability that any given individual will be in the ...

PROC SURVEYSELECT provides a variety of methods for selecting probability-based random samples. With probability sampling, each unit in the survey population has a known, positive probablity of ...

BACKGROUND Surveys of immigrants face challenges of coverage, representativeness, and response rates. Longitudinal studies of immigrants and ethnic minorities, which have potential to address pressing ...

Volatile organic compounds (VOCs) are an important indoor air quality issue because they are associated with increased long-term health risks and people spend more than 90% of their time indoors. Past ...