Description
Calculate a prediction interval's midpoint and signed deviation from an actual value.
Prediction metrics depend on the observation definition, reference forecast, denominator sign and aggregation. A single error contribution differs from a mean score or normalized skill measure. Interval midpoints, squared probability errors and seasonal-denominator labels must retain the exact convention before models are compared.
Calculate a prediction interval's midpoint and signed deviation from an actual value.
When to use this tool
Use Interval Midpoint Bias Contribution when you already have lowerPrediction, upperPrediction, actual and need to calculate a prediction interval's midpoint and signed deviation from an actual value.
How to use the tool and how it works
- Enter lowerPrediction, upperPrediction, actual. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read midpoint, midpointMinusActual. Use the output convention below.
Require upperPrediction>=lowerPrediction; midpoint=lower/2+upper/2 and bias contribution=midpoint-actual.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| lowerPrediction | Lower Prediction | Required. Finite number. |
| upperPrediction | Upper Prediction | Required. Finite number. |
| actual | Actual | Required. Finite number. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| midpoint | Midpoint | Required. Finite number. |
| midpointMinusActual | Midpoint Minus Actual | Required. Finite number. |
{
"input": {
"lowerPrediction": 8,
"upperPrediction": 12,
"actual": 9
},
"output": {
"midpoint": 10,
"midpointMinusActual": 1
}
}Limitations and assumptions
- A midpoint contribution is not interval coverage, uncertainty validity or a full forecast-bias estimate.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Calculate the complete documented metric over the intended observations and reference baseline. Review missing/zero actuals, aggregation weights and outcome coding; one contribution or source label does not establish overall forecasting quality.
References
Similar or alternative tools
- Mape Absolute Vs Signed Actual Policy
Calculate one absolute prediction error under a chosen actual-value denominator convention.
- Brier Reference Class Contribution
Compare predicted and reference single-class squared probability errors.