Docs
Results sheet
Free writes a summary WhichForecast_Results sheet (applied method, n, forecast + 95% interval). Pro adds a formatted workbook: full rankings, named tables, params, and a WF_Note sheet, plus a client-side PDF of the method note. JSON and the watermarked note stay Free. Nothing uploads the raw series.
Glossary
MASE (scale-free error), ADI (average inter-demand interval), PI (prediction interval), FVA (forecast value added vs naive), Method DNA.
Method tutorials
Every catalog method has a public page — assumptions, when to use or avoid, a worked sketch, and a chart. Start at Methods. The add-in “More information” link opens the matching URL.
Developer sideload
Run the task pane locally over HTTPS and sideload manifest.xml. See the repository README.
Sister product
WhichDist ranks probability distributions with AICc. Different engine; same family.
Understanding the error metrics
- MASE — mean absolute scaled error vs a naive (or seasonal naive) benchmark. Leads the ranking. Lower is better; below 1 beats the naive.
- MAE / RMSE — absolute and squared-error scales in the series units. RMSE penalizes large misses more.
- sMAPE — symmetric percentage error. Prefer this over MAPE when zeros exist.
- MAPE — warned when zeros would make it explode or lie.
- ME (bias) — e = y − ŷ. Positive ME means the forecast was below the actuals on average (under-forecast).
- FVA — forecast value added vs naive: does the method beat the simple baseline on this series?