Completely agree on the confusing terminology there. IMO that should be: > The moment of capturing a measurement is known as a metric sample. The mental model

Completely agree on the confusing terminology there. IMO that should be: > The moment of capturing a measurement is known as a metric sample. The mental model I hold is the metric is the actual value. This may be discrete (e.g. a packet counter) or some continuous value (e.g. a voltage in you ECG example). It can then be observed at some time/value delta interval or summarised into other time series based on what you're hoping to capture.