Sensory Register
• Duration: few milliseconds up to 30 seconds a lifetime( few milliseconds, up to 30 seconds, a lifetime )
• Capacity: very large a few items unlimited( very large, a few items, unlimited )
• Encoding: either echoic or iconic acoustic semantic( either echoic or iconic, acoustic, semantic )

Short Term Memory:
• Duration: up to 30 seconds (without rehearsal) a few seconds forever( up to 30 seconds (without rehearsal), a few seconds, forever )
• Capacity: 7 +/- 2 items up to 10 items millers magic number 9( 7 +/- 2 items, up to 10 items, millers magic number 9 )
• Encoding: mainly acoustic echoic semantic( mainly acoustic, echoic, semantic )

Peterson and Peterson- investigated the duration capacity encoding( duration, capacity, encoding ) of short-term memory long-term memory sensory register( short-term memory, long-term memory, sensory register ), using a lab experiment field experiment quasi experiment( lab experiment, field experiment, quasi experiment ) in which participants had to recall consonant trigrams random letters groups of three( consonant trigrams, random letters, groups of three ) e.g. TGH. To prevent rehearsal participants were given an interference task distraction( interference task, distraction ) e.g. counting backwards in threes from a specified random number . Participants were asked to recall trigrams after intervals of 3, 6, 9, 12, 15 or 18 2, 4, 8, 10, 12 or 14 4, 8, 12, 16, 20 or 24( 3, 6, 9, 12, 15 or 18, 2, 4, 8, 10, 12 or 14, 4, 8, 12, 16, 20 or 24 ) seconds.

They found the longer the interval delay the less trigrams more trigrams( less trigrams, more trigrams ) were recalled. Participants were able to recall 80% 20% 47%( 80%, 20%, 47% ) of trigrams after a 3 seconds delay. However, after 18 seconds less than 10% 94% 30%( less than 10%, 94%, 30% ) of trigrams were recalled correctly. this supports that the short-term memory has a limited duration when rehearsal is prevented.

Miller suggested that most people store about seven six five( seven, six, five ) items in their short term memory long term memory( short term memory, long term memory ) e.g. numbers, letters or words he argued that the capacity duration encoding( capacity, duration, encoding ) of the short term memory could be enlarged by grouping items together into meaningful 'chunks' and called this process 'chunking grouping pairing( chunking, grouping, pairing )'. Miller therefore suggested that about 7+/- 2 items 7 +/- 4 items 6 +/- 2 items( 7+/- 2 items, 7 +/- 4 items, 6 +/- 2 items ) can be stored in the STM depending on chunking>

Suggested that encoding in the STM is acoustic semantic( acoustic, semantic ). As he found ppt's recalled less more( less, more ) when the letters they had to recall were acoustically similar semantically similar( acoustically similar, semantically similar ) than if they were acoustically dissimilar semantically dissimilar the same( acoustically dissimilar, semantically dissimilar, the same ).

Long Term Memory:
• Duration: Unlimited up to an hour without rehearsal 24 hours( Unlimited, up to an hour without rehearsal, 24 hours )
• Capacity: Unlimited 1000 memories as much as we have room for( Unlimited, 1000 memories, as much as we have room for )
• Encoding: Semantic acoustic iconic( Semantic, acoustic, iconic )