jacobs' study 1887

• he showed participants random strings of letters and ask them to recall the letters they saw in the order they were presented to them
• across the trail, Jacobs' increased the length of the string of letters to determine the maximum number of letters participants could recall
• he found that most participants could correctly recall 7 letters or digits
• he found that the capacity of short term memory was 7+-2
• by showing that the capacity of short-term memory was set at 7 +/-2 digits or letters, Jacobs’ study provides evidence that the capacity of short-term memory is limited