Accuracy of Judgmental Forecasting of Time Series

Experiments contrasted judgmental and objective forecast methods. Judgmental methods included “eyeball” extrapolation of time‐series plots and judgmental adjustment. Objective methods included Box‐Jenkins (BJ), Carbone‐Longini AEP filtering (CL), Holt‐Winters (HW), and other smoothing techniques. Objective methods proved more accurate than eyeball extrapolation. However, judgmental adjustment improved the accuracy of some objective forecasts.