Free recall is a basic paradigm in the psychological study of memory. In this paradigm, participants study a list of items on each trial, and then are prompted to recall the items in any order (hence the name "free" recall). Items are usually presented one at a time for a short duration, and can be any of a number of nameable materials, although traditionally, words from a larger set are chosen. The recall period typically lasts a few minutes, and can involve spoken or written recall. The standard paradigm involves the recall period starting immediately after the final list item; this can be referred to as Immediate Free Recall (IFR) to distinguish it from Delayed Free Recall (DFR). In delayed free recall, a short distraction period is interpolated between the final list item and the start of the recall period. Both immediate free recall and delayed free recall have been used to test certain effects that appear during recall tests, such as the primacy effect and recency effect.