Random sampling by using lots is an old idea, mentioned several times in the Bible. In 1786, Pierre Simon Laplace estimated … See more

Successful statistical practice is based on focused problem definition. In sampling, this includes defining the "population" from which our sample is drawn. A population can be defined as including all people or items with t… See more

In the most straightforward case, such as the sampling of a batch of material from production (acceptance sampling by lots), it would be most desirable to identify and measure every single item in the population and to inclu… See more

Within any of the types of frames identified above, a variety of sampling methods can be employed individually or in combination. Factors commonly influencing the choice between these designs include:
• Nature … See more

Sampling schemes may be without replacement ('WOR' – no element can be selected more than once in the same sample) or with replacement ('WR' – an element may appear multiple times in the one sample… See more

Formulas, tables, and power function charts are well known approaches to determine sample size.
Steps for using sample size tables:
1. Postulate the effect size of interest, α, and β.… See more

Good data collection involves:
• Following the defined sampling process
• Keeping the data in time order
• Noting comments and other contextual events… See more