In the new edition of The Complete Companion (which is now on sale if you haven’t had your copy!) we have presented an updated diagram of the multi-store model which may confuse some people because it is different to the one given in some books – for a reason. The model was first proposed by Atkinson and Shiffrin in 1968, consisting of only two stores – short- and long-term memory. The third store – sensory memory – was added later. This early model is often shown with information being lost through forgetting (as shown below).

In 1971 Atkinson and Shiffrin produced a slightly different diagram, indicating how information is retrieved from memory – via the short term store, as shown below. No mention was made of forgetting.

Work by Craik and Lockhart on the levels of processing (e.g. 1972) led to a refinement of the concept of ‘rehearsal’. Craik and Lockhart distinguished between simple maintenance rehearsal and more complex or ‘deep’, elaborative rehearsal which may be necessary for enduring long-term memories. This more recent formulation is given in The Complete Companion as shown below.