Why do the rankings use five years of citations data?
In the early years the ranking used ten years of data from the Essential Science Indicators (ESI). Feedback suggested that this lengthened the time it takes for an excellent, dynamic and productive, but young institution to reveal its excellence in the rankings. Since results are published annually, it is important to recognise contemporary excellence. Citation dynamics varyby subject, however, so it is possible in the future that the length of the citation window will differ by subject or faculty area.
