A cognitive-psychological test used to measure short-term memory and the effect of interference on retention of information. In this test, participants are shown a set of elements (most often trigrams such as three consonants) that they must memorize. They are then asked to complete a distracting task (such as counting backwards by three or solving simple arithmetic problems) for a set amount of time, usually between 3 and 18 seconds. After the delay, the participants must reproduce the original elements. The task is designed to study memory impairment over time and how interference affects the ability to retain information. The results generally show that memory efficiency deteriorates as the length of the distraction period increases, providing insight into the duration and vulnerability of short-term memory.