Answer: (1) intuitive judgment method This is a general term for qualitative prediction methods. This method has a wide application range, low cost and less time consumption, but it is difficult to provide the predicted value based on accurate data due to the subjective factors of forecasters. This method is often used when there are few or inaccurate data. Qualitative prediction methods mainly include collective judgment method and expert opinion method. (2) Historical extension method This is the general term for quantitative forecasting methods. Under the condition that we have some statistical data and the future of the predicted object is less affected by unexpected factors, we can get satisfactory prediction results by choosing appropriate mathematical models for quantitative prediction. However, because it is impossible to consider all factors in the selection and establishment of mathematical models, the results of quantitative prediction will inevitably have errors. This method includes simple average method, moving average method, weighted moving average method, trend prediction method, exponential smoothing method and seasonal index method.