A time-relevant indicator of how frequently a journal’s items published in a given year are cited within the same year. Formula (Year Y)=Citations received in Year Y ÷ Number of items published in Year Y How to interpret: Higher values indicate more same-year citation activity per published item. Because citations often take time to accumulate, AIF values may be lower early in the year and increase as the year progresses.
Measures the average citations per published item over the last 18 months, then scales the value by 18/12 to reflect an 18-month normalized indicator. Formula:(Citations in Y + 0.5 Citations in (Y-1)) /( Number of publication in Y+ 0.5 Number of publication in (Y-1))× (18/12)