Atkinson and Shiffrin
They thought that memory passes through a series of processes/stores in order to remember information. Each of these stores have different characteristics.
Information according to Atkinson and Shiffrin passes thorugh three stages, which can be used to explain why some memories remain permanent
Sensory Memory: lasts a few seconds, 0 to 5 pieces of information, information gets encoded
Short Term Memory: lasts 18-30 seconds, 5 to 9 pieces of information, information is rehersed so it can be transferred into long term memory, if not rehersed it will be forgotten
Long Term Memory: lasts unlimited time, unlimited information, information is transferred from short term memory to long term then retrieved to remember.
Peterson and Peterson
Peterson and Peterson wanted to see if rehearsal was necessary in order for people to remember information. They gave participants tri-grams and asked them to complete short tasks to prevent the rehearsal and asked to recall the tri-grams after completing the task. The results were only 10% of tri-grams were remembered after 18 seconds. If we prevent rehearsal we forget.
lab experiment therefore has low ecological validity. The sample was small and only in Americans therefore you cannot apply it to a larger amount of people so you cant generalise. It doesn't take into account individual differences
A study to support interference is Postman and Underwood. Their aim was too see if new learning interferes with previous learning. Lab experiment. Participants were divided into two groups. Group A were asked to learn a list of pair words, they were then asked to learn a second list of pair words. Group B was only required to remember one list only.
Group B were more accurate to recall the first list than Group A, this is because in Group A the second list interfered with the first and made it harder to remember.