Glossary - Tripoli Docs

arithmetic mean: $\bar{x} \quad$ The sum of the data points divided by $n$ . One (but not the only!) estimate of the average value.
confidence interval: A range that should contain the true value you’re trying to measure if you were to repeat the measurement many times. For instance, if you repeated a measurement many times over and calculated the 95 percent confidence interval for each of the measurements, then you’d expect the true value to lie inside 95 percent of the confidence intervals you calculated.
standard deviation: $\sigma_{} \quad$ An estimate of the scatter in the data about the mean.
standard error: $\sigma_{\bar{x}} \quad$ An estimate of the uncertainty in the mean after repeated measurements.