Mean Forecast Error Calculator
Calculates signed average forecast error to reveal directional bias. The worked condition keeps the method and source values visible for an independent check.
Describe the observed sequence for the stated inputs
Mean forecast error
The boundary of the claim before reporting
Recalculate one intermediate quantity from mean(actual−forecast) and work back from the displayed answer. The source values should be enough for another analyst to reproduce mean forecast error.
Use a boundary case when possible: equal values, a probability near zero, a window of two, or a rate of zero. Expected limiting behavior is often more informative than another decimal place. The chosen mean forecast error convention remains attached to the source record. Before reusing this result, write down the observed scale, model boundary, and convention behind the displayed value. That record separates a changed dataset from a changed definition and gives the next analyst a clear route back to the original calculation.
A second look at the condition under the stated model
The number answers one statistical question. It does not establish causation, model fit, representativeness, or a useful decision threshold by itself. The page-specific quantity is mean forecast error.
Practical meaning depends on the measurement scale and consequences. State the comparison or benchmark before presenting mean forecast error as evidence. Before reusing this result, write down the observed scale, model boundary, and convention behind the displayed value. That record separates a changed dataset from a changed definition and gives the next analyst a clear route back to the original calculation.
A direct numerical check when the sample changes
Positive and negative misses can cancel, so MFE should be read beside an absolute error measure. Outliers, dependence, extrapolation, seasonality, or a mismatched convention can change the appropriate method. The page-specific quantity is mean forecast error.
Choose an alternative because the design or data require it, not because its result is more favorable. Preserve the selected convention in the report. The chosen mean forecast error convention remains attached to the source record.
When another method fits during an independent review
Save the entered values, units, formula version, exclusions, and unrounded output with mean forecast error. A copied number without its condition is not reproducible.
Round after downstream calculations are complete. Extra digits cannot repair a biased sample, unstable fit, or unsupported distributional assumption. The chosen mean forecast error convention remains attached to the source record.
For another time-series question, compare root mean squared forecast error and tracking signal.
The design boundary at the chosen parameters
Construct a second plausible scenario that changes one uncertain input while keeping the rest coherent. Compare the statistic and practical interpretation across both cases. The page-specific quantity is mean forecast error.
If a small defensible change reverses the conclusion, report the sensitivity rather than hiding it behind one preferred scenario. The chosen mean forecast error convention remains attached to the source record.
Where the method applies before comparing methods
Calculates signed average forecast error to reveal directional bias. The displayed relationship is mean(actual−forecast), and each symbol is tied to a labeled field. The page-specific quantity is mean forecast error.
The example MFE is 0.00 units. This example is a numerical check, not proof that the model describes every dataset. The chosen mean forecast error convention remains attached to the source record.
Before reporting this result during an independent check
For the saved dataset, can a missing value be entered as zero?
Only when zero was observed; missingness and a measured zero carry different meanings. The reported quantity here is mean forecast error.
At the stated exposure, how many digits should be reported?
Retain guard digits during checking, then round to the resolution supported by the source measurement. The reported quantity here is mean forecast error.
When the fitted range moves, does this result prove a causal relationship?
No. A robust summary or forecast arithmetic does not replace design, measurement, or substantive reasoning. The reported quantity here is mean forecast error.
During an independent check, what belongs in the saved record?
Preserve the source data, formula convention, units, exclusions, and method version. The reported quantity here is mean forecast error.
For the worked condition, what should be checked before reusing this result?
Keep the inputs, units, method name, exclusions, and unrounded output together. The reported quantity here is mean forecast error.