# Estimating uncertainty in physical measurements, observational and environmental studies: Lessons from trends in nuclear data

*Proceed. ISUMA '93 Second International Symposium on Uncertainty Modeling and Analysis*, IEEE Computer Society Press (1993), pp. 310-317

## Abstract

The time trends in the sequential series of measurements of the same physical quantity
show a general pattern: the normal distribution grossly underestimates the probability of
large deviations from the true values; the probability is well described by exponential functions.
By analogy with physical measurements, the results indicate that the usual 95% confidence
intervals in epidemiology and environmental studies should be expanded to account for
unsuspected systematic errors.

#### Keywords: uncertainty, confidence intervals, overconfidence, systematic errors, physical measurements, epidemiological studies, environmental studies

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