not significant, indicating that changing operator has no more impact on the result than repeating the measurement ten times; significant, indicating that changing operator has an impact on the result ...

Christenson, Charles. "Managing against Expectations (A): An Introduction to Profit Variance Analysis." Harvard Business School Background Note 182-013, July 1981.

Variance is a key statistical measure that represents the degree of spread or dispersion in a dataset. It quantifies how much individual data points differ from the mean (average) value of the dataset ...