Jacobs - capacity in stm

• jacobs used the serial digit span technique (presenting items in a series)
• Jacobs used letters/numbers but no 7 or W
• jacobs presented the item every half a second and the pts had to recall them in order
• the string of numbers increased by one each time until no more could be recalled
• he found the average digit span was just over 9 items while average letter span was just over 7
• he also found pts who were younger could remember higher amounts of items than older pts
• he concluded the capacity of stm is very limited to between 5-9 items depending on type of material and age