Meaning
Range of values within which an unobserved parameter falls with a specified probability according to the available data. A bayesian credible interval differs from a frequentist confidence interval by treating the parameter as a random variable rather than a fixed unknown. It incorporates prior beliefs and new observations to bound the uncertainty of a model prediction.
This range provides a direct probabilistic statement about the location of a physical constant or a production variable.
Probability Density
Calculation of this range depends on the shape of the posterior distribution. Every point inside the interval has a higher probability density than any point outside it when using the narrowest possible bounds. High probability regions indicate where a process is most likely to operate.
Inference Application
Estimating a bayesian credible interval allows an engineer to quantify the risk of a process exceeding a safety limit. It provides a formal way to update performance expectations as more sensor data arrives from the plant floor.
Uncertainty Management
Precision in these intervals narrows as the volume of evidence grows. Broad intervals early in a project signal a lack of information that may justify delaying full-scale production. Narrowing the range is a requirement for final certification.
The cost of calling a result early when intervals are wide is the high probability of a false positive in capability. Every calculation must be audited against the original prior to ensure the logic holds.