## Quick Reference

A measurement of the skill of a forecast. The Priestley skill score, *P*, applies to value forecasts (such as forecasts of temperature). Let *f** _{i}* denote a forecast, and let

*o*

*denote the subsequent observed value, with*

_{i}*ō*denoting the mean of a set of

*n*observed values. Then

*P*is given by The Brier score was introduced in 1950 to assess the accuracy of probabilistic weather forecasts (e.g. ‘There is a probability

*p*

*of rain tomorrow’). Denoting the actual weather outcome by*

_{i}*o*

*(equals 1 if the event occurs, and 0 if it does not) the Brier score,*

_{i}*B*, is given (for

*n*forecasts) by The smaller the value of

*B*, the more skilful the forecasting procedure. If

*B*

*denotes the Brier score for a standard forecasting system, then*

_{s}*S*, given by is called the Brier skill score.

**From:**
skill score
in
A Dictionary of Statistics »

*Subjects:*
Probability and Statistics.

## Related content in Oxford Index

##### Reference entries

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.