Temparory and could be overcome using cues
Tulving and Psotka 1971 gave pp a list of words organised into three categories in which they did not know.
The recall of words for the first list averaged of to 70%
This decreased as they learned an additional list
At the end of the study they were given the category for the list and it rose to 70% again
Suggests that it causes a temporary loss of accessibility to material that is still in the LTM, a finding not predicted by interference theory