Abstract: By selecting window width from one to five, window analysis model is used to carry out a dynamic study on scientific research efficiencies at the universities in different provinces of China during the period of 2003-2007. By comparing the results of different window widths, Technical Efficiency (TE), and pure technical efficiency (PE) at the universities in different provinces of China are decrease and Scale Efficiency(SE) is irregularly varied with the increase of window widths. Scientific research efficiencies have different sensibility to the window width in different years. With the different selection of window widths, scholars would obtain radical different conclusions on the long term changing trend of TE, PE, and SE. For the problem how to determine the optimal window width, a new analysis method is thieoritacally proposed, the study determines the optimal window width, a more researnoable window analysis model that is suitable to the dynamic analysis on scientific research efficiencies at the universities of China is built. The dynamic results are compared with the results based on conventional DEA models, and great variances between two of them are found, it is further proved that setting up a window analysis model with an optimal window width to conduct a dynamic study is necessary and the results further accord with the reality of scientific research activities.

Key words: data envelopment analysis, window analysis model, scientific research efficiency, window width