Evaluation - Supporting research evidence - supported by research studies that show that STM ands LTM are indeed qualitatively different. For example, Baddely found that we tend to mix up words that sounds similar when using out STMs. By we mix up words that have similar meaning when using our LTM. The strength of this is that the study clearly shows that coding in STM is acoustic and LTM is semantic. This supports the MSM's view that these two memory stores are separate and indeoendent. Further support is given by all the studies of coding, capacity and duration.
There is more than 1 type of STM. The MSM states that STM is a unitary store. However, evidence from people suffering with amnesia shows that this cannot be true. For example, Sallice and Warrington (1970) studied a patient known as KF. They found that KF's short term memory for digits was poor when they read them out to him. But his racal was much better when he was able to read the digits to himself. Further studies have shown that there could be another short term store for non-verbal sounds such as noises. The unitary STM is a limitation of the MSM because ressearch shows that at the very least there must be one short-term store to process visual information and other to process auditory information (WMM)
There is more than one type of reheasrsal - according to MSM, what matters in rehearsal is the mount of it that you do. So the more you rehearse information, the more likely you are to remember it . However, Craik and Watkins found that t what really matters about rehearsal is the type. Maitenance rehearsal does not transfer info into LTM, it just maintains STM. Elaborative rehearsal is needed for long-term storage. This happens when you link information to existing knowledge or thinking about the meaning of the information. This is a limitation because it is another research finding that cannot be explained by the model
There is more than one type of LTM. There is a lot of research evidence that LTM, like STM is not a unitary store. For example, Tulving stated that we have 3 different types of LTM; procedural, episodic and semantic
Artificial meterials used in studies to support MSM