WEAKNESSES- reductionist, suggests human memory can be influenced by other factors e.g.- emotional state, anxiety can influence accuracy of an eye witness testimony. ignores influence of emotion and motivation on cognition, too simplistic and less reflective of real life behaviours. machine reductionist, human behaviour is too complex - make errors, forget and have free will over actions, computer does not. borrows computer science terms e.g.- encoding, storage and retrieval but doesn't accurately describe human brain processes, human mind is far too complex than this and model is limited