interference theory

• A lab experiment was conducted which included the participants (who were split into two groups) to remember a list of paired words, for example, cat-tree, jelly-moss.

  The experimental group had to learn another list of words where the second paired word is different, for example, cat-glass, jelly-time.
• When asked to recall the words on the first list, it was found that the recall of the control group was more accurate and suggests that learning items in the second list interfered with the participants' ability to recall the list.

  This is an example of retroactive interference and so this study supports the interference theory for forgetting.
• However, conflicting evidence for interference from Tulving et al who gave participants five lists of words which were organised into categories.

  Recall was roughly 70% for the first word list but this fell as participants were given each additional list to learn, presumably due to interference.

  However, at the end, they were given a cued recall test where they were told the categories as a clue and recall rose again to about 70%.
• This finding suggests that interference may not be a valid explanation since it explains why performance became worse as more lists were learned however, according to the theory, the words should disappear from memory and no longer be available for recall.

  And so, even with a cued recall test, performance should be poor as the words are no longer stored in LTM.

  However, the fact that recall returned to high levels suggests that the words were still stored in LTM and they were available, just not accessible. This decreases the validity of interference theory as an explanation for forgetting.
• A strength of this theory is that many lab experiments have been carried out to support it and these experiments control the effect of irrelevant influences which strengthens the internal validity of the explanation for forgetting.

  On the other hand, the majority of research being lab experiments is also a limitation since the artificial tasks of learning lists of words makes it difficult to generalise the findings to everyday life since such trivial tasks are not similar to the things we try to remember daily.
• This is an issue as this makes interference more likely in the lab which suggests that interference may not be as likely an explanation for forgetting in everyday life as in the lab.
• Furthermore, Baddeley states that the tasks given to participants are too close to each other, and in real life, these events are more spaced out.

  Baddeley & Hitch (1977) asked rugby players to try and remember the names of the teams they had played so far in that season, week by week.

  The results showed that accurate recall did not depend on how long ago the matches took place, but rather the number of matches they played in the meantime.

  The study supports the interference theory as it suggests that it can apply to at least some everyday situations.