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A-Factor (absolute factor; AF)
number associated with every element in a collection. A-Factor determines how much intervals increase in the learning process. The higher the A-Factor, the faster the intervals increase. You can see A-Factors in the Element data window. For items, A-Factors reflect item difficulty. For topics, A-Factors modulate topic priority (by affecting the frequency of exposition). The higher the A-Factor the easier the item. The most difficult items have A-Factors equal to 1.2. For items, A-Factor is defined as the quotient of the second optimum interval and the first optimum interval used in repetitions (read more: SuperMemo Algorithm SM-15). For topics and tasks, A-Factor is interpreted as the number by which the current interval should be multiplied to get the value of the next interval (as it was the case with E-Factors in early versions of SuperMemo).