Standard deviation (SD) is used to figure out how “spread out” a data set is.
Standard error (SE) or Standard Error of the Mean (SEM) is used to estimate a population’s mean. For example if you have a large population, then different samples drawn from that same population would in general have different values of the sample mean. The standard error of the mean is the standard deviation of those sample means over all possible samples drawn from the population.
Standard Error of the Mean is calculated by dividing the standard deviation by the square root of the sample size.
- Definition – Standard deviation
- Standard Error of the Mean (Biostatistics Text)
- Measures of Spread or Variation
Calc of SE from SD