The arithmetic mean adds the values and divides by their count. The median identifies the middle of the ordered values, using the average of the two central values when the count is even.
A very large or small value can move the mean considerably while leaving the median less affected. That does not make one summary universally better. The choice depends on the question and the distribution being described.
Look at the underlying values or a useful distribution view alongside either summary. Include the count and any relevant grouping. A single measure can be convenient, but the shape of the collection often explains why two reasonable summaries tell different stories.
- Identify which summary is being reported.
- Look for unusually large or small values.
- Keep the distribution and count in view.
Picture this situation.
A group of ordinary task durations and one unusually long task can make different summaries tell different stories. Inspect the values behind either summary.
A second way to look.
Look for the comparison behind the visual impression. The baseline, time window, and group definition can change what a pattern seems to mean.
Follow a related question
Distinguish prompts from finished answers.
A template with room to thinkRead the task and scoring method.
A benchmark measures a defined taskKeep learning
Related background to continue exploring this subject.
NIST: statistical engineering NIST: the International System of Units
