1.3 Prediction step (1) Select the forecasting method to be appropriate Because any particular method is based on certain assumptions, and any assumption can not summarize the intricate relationships in the real world, it is important to choose appropriate prediction methods (2 )Method of model selection The first is to determine the reserved portion of the sample according to certain riteria such as MAPE(the Mean absolute Percentage Error) Secondly, it depends on the most suitable time series for each model, such as the annual series using the trend correction exponential smoothing method;1.3 Prediction step (1) Select the forecasting method to be appropriate Because any particular method is based on certain assumptions, and any assumption can not summarize the intricate relationships in the real world, it is important to choose appropriate prediction methods. (2) Method of model selection The first is to determine the reserved portion of the sample according to certain criteria such as MAPE (the Mean Absolute Percentage Error); Secondly, it depends on the most suitable time series for each model, such as the annual series using the trend correction exponential smoothing method;