An Improved Indicator of Impact Factor Based on Journals´ Life Cycles

In this paper we introduce a new modification of calculating the Impact Factor(IF) for journals based on the variation of papers\´ popularity in different journals and research fields over time, which we call "life cycle". The impact factor value for a journal calculated by the proposed method is called Improved Impact Factor (IIF). Papers in forty journals published from 1980 to 2014 are selected and examined, and the impact factor values from IF and IIF methods then compared. The position of the journals ranked by impact factors obtained from IF method were different from those from the IIF method. It is concluded that IIF is more suitable for journals with longer life cycle and journals with longer IIF.