The Distinction Between STM and LTM

When psychologists use the free recall technique it produces a characteristic serial curve. This is thought to be because words at the beginning of a list have been rehearsed and have passed to LTM meaning they can be recalled at the time of rehearsal (the Primacy effect). Words at the end are still circulating in STM and can be easily retrieved (recency effect). While words in the middle have had little time for rehearsal and have been displaced by later items in the list (asymptote) Glanzer and Cunitz (1966) showed this functional dissociation in their experiment. 

Glanzer and Cunitz (1966)
Aim: To find functional dissociation curve in STM and LTM
Procedure: There were two conditions in the experiment
- In Condition One, participants were asked to recall the words immediately after they had been presented
-In Condition Two, participants were given a distractor task after the words had been presented and had to count backwards in 3s for 30 seconds before they were asked to recall words. 
Results:In condition one they found the expected serial position curve. However, in condition 2, they found that the distractor task had been disrupted the recency effect and words from the last part of the list were not recalled well. 
Conclusions: They explained that the task of counting backwards had displaced the last few words in the list from the fragile STM but the task had not affected earlier words because they had been rehearsed and passed to LTM
Evaluation: Lab so highly controlled. However, does not represent how memory works in daily life. 
Researchers had to gain consent and debrief them afterwards so was ethical