Repeatability - Establishment

Establishment

According to the Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results, the following conditions need to be fulfilled in the establishment of repeatability:

• the same measurement procedure
• the same observer
• the same measuring instrument, used under the same conditions
• the same location
• repetition over a short period of time.

Repeatability methods were developed by Bland and Altman (1986).

If the correlation between separate administrations of the test is high (e.g. 0.7 or higher as in this Cronbach's alpha-internal consistency-table), then it has good test-retest reliability.

The repeatability coefficient is a precision measure which represents the value below which the absolute difference between two repeated test results may be expected to lie with a probability of 95%.

The standard deviation under repeatability conditions is part of precision and accuracy.