Several biases and inefficiencies are commonly associated with the judgmental extrapolation of time series even when forecasters have technical knowledge about forecasting. This study examines the effectiveness of using a rolling training approach, based on feedback, to improve the accuracy of forecasts elicited from people with such knowledge. In an experiment forecasters were asked to make multiple judgmental extrapolations for a set of time series from different time origins. For each series in turn, the participants were either unaided or they were provided with feedback. In the latter case, following submission of each set of forecasts, the true outcomes and performance feedback were provided. The objective was to provide a training scheme, enabling forecasters to better understand the underlying pattern of the data by learning directly from their forecast errors. Analysis of the results indicated that the rolling training approach is an effective method for enhancing judgmental extrapolations elicited from people with technical knowledge, especially when bias feedback is provided. As such it can be a valuable element in the design of software systems that are intended to support expert knowledge elicitation (EKE) in forecasting.