Memory Short-term 

Short-term memory allows recall for a period of several seconds to a minute without rehearsal. Its capacity is also very limited - George A. Miller , when working at Bell Laboratories, conducted experiments showing that the store of short-term memory was 7±2 items . Modern estimates of the capacity of short-term memory are lower, typically on the order of 4–5 items, however, memory capacity could be increased through a process called chunking. For example, in recalling a ten-digit telephone number, a person could chunk the digits into 3 groups - first, the area code , then a three-digit chunk & lastly a four-digit chunk . This method of remembering telephone numbers is far more effective than attempting to remember a string of 10 digits this is because we are able to chunk the information into meaningful groups of numbers. Herbert Simon showed that the ideal size for chunking letters & numbers, meaningful or not, was three. This might be reflected in some countries in the tendency to remember telephone numbers as several chunks of 3 numbers with the final four-number groups, generally broken down into 2 groups of two.

Short-term memory is believed to rely mostly on an acoustic code for storing information, & to a lesser extent a visual code. Conrad found that test subjects had more difficulty recalling collections of letters that were acoustically similar . Confusion with recalling acoustically similar letters rather than visually similar letters implies that the letters were encoded acoustically. Conrad's study however, deals with the encoding of written text, thus while memory of written language might rely on acoustic components, generalisations to all forms of memory cannot be made.

However, some individuals have been reported to be able to remember large amounts of information, quickly, & be able to recall that information in seconds.