Survey mode effects linked to unit nonresponse and screening procedures were estimated in a study of self-reported tobacco, alcohol, and illicit drug use. Two samples of the same population were drawn ...

The jackknife estimation procedure is used to estimate Brillouin's and Simpson's indices of diversity when sampling is done by selecting quadrats. Using simulated ...

Conflicting findings are often reported in microbiome association studies, which could be due to insufficient sample sizes and numerous confounders. A new study, utilizing two large-scale human ...

Generally, we expect that surveys representing the same target population should produce estimates that are consistent with one another; that is, measures taken at roughly the same time should not ...

By Courtney Kennedy, Andrew Mercer, Scott Keeter, Nick Hatley, Kyley McGeeney and Alejandra Gimenez As the costs and nonresponse rates of traditional, probability-based surveys seem to grow each year, ...

An illustration of the various elements of the overall Mars Sample Return effort. Credit: NASA/JPL-Caltech WASHINGTON — NASA has confirmed that one scenario for the cost of its Mars Sample Return (MSR ...

Suppose you buy a major asset like a new piece of machinery. Under standard accounting rules, you cannot write off the cost of the machinery in the year you incur the expense. Rather, you have to ...