STA 210 Lecture Notes - Lecture 4: Simple Random Sample, Sampling Distribution

• School: University of Kentucky
• Department: Statistics
• Course: STA 210
• Professor: Jeff Modenbach

Document Summary

Sampling error is also known as margin of error. The variability seen in a statistic from sample to sample is called sampling variability. Sampling variability from sample to sample is predictable. If sample is not a probabilistic sample, then it will be very difficult to do the formal inference with integrity. If you were to do the sampling over and over and plot the different statistics you would get. The plot is called a sampling distribution. In particular, it would be bell-shaped and peak above the parameter from the population. Simple formulas are available for the margin of error and associated confidence intervals, provided the data were collected in a simple random sample, or similarly statistically correct fashion. The margin of error is a nice mathematical way of addressing sampling variability, also called random sampling error . There are lots of other errors that can affect data collection and the margin of error simply doesn"t apply.