Learn how representative samples and random samples differ and why combining them minimizes sampling bias for accurate data.

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 ...

where is the true probability of observing the jth response level in the ith population. The product multinomial distribution is simply the product of two or more individual multinomial distributions ...

Producers of infant formula employ comprehensive food safety systems, including product testing to ensure those systems are working. A new study from the University of Illinois Urbana-Champaign finds ...

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 ...