First, preemptive and preventive uses of force are often justified by claiming either that there is substantial risk of a future attack or that it is difficult to ascertain how dangerous the target is.
Short-Term Memory: Up to 7 Items, But Highly Volatile. Many psychology experiments have shown that our short-term memory can hold only a limited number of separate items. The average is about 7 items, plus or minus 2, depending on the individual. You can easily confirm this by reading someone a series of words that have no connection with one another, then asking this person to repeat them.
The average span for letters was 7.3 and for numbers it was 9.3. The duration of short term memory seems to be between 15 and 30 seconds, according to Atkinson and Shiffrin (1971). Items can be kept in short term memory by repeating them verbally (acoustic encoding), a process known as rehearsal.