Si

Si: Introverted Sensing types are characterized by retrospective analysis, which consists of analyzing past events, consciously and unconsciously, in order to predict the future. This should not be confused with Introverted Intuition (Ni), which analyzes patterns in the present to predict the future. Introverted Sensing does not figure out patterns; instead, it uses known experiences and the knowledge of what happened to predict the future. An example would be if an Si user never leaves a tip, but remembers that they once tipped and got better service. They will then predict that if they repeat this in the future and tip again, they will receive better service.

Like all introverted functions, Si looks inward. Given the very nature of Si analysis, Si is the type where we see the greatest amount of difference between users. This is because Introverted Sensing, being experience-oriented, is ultimately heavily shaped by what users have lived through, as their past is constantly shaping their vision of the future. This means that Si users develop from experience much more than other types.