Coding, duration, capacity eval

Question 1

Artificial stimuli (Coding)

Answer 1

Main limitation is that it used artificial stimuli rather than meaningful material. This word list had no meaning to ppts. So cannot be generalised to other kinds of memory tasks. E.g. when we are processing more meaningful info people use semantic coding even for STM tasks. Limitation because findings from this study have limited application

Question 2

LTM may not be exclusively semantic (Coding)

Answer 2

LTM appears to be semantic but not always. Frost showed that LTM recall was related to visual as well as semantic categories. Furthermore Nelson and Rothbart found evidence of acoustic coding in LTM. Limitation because coding in LTM is not simply semantic but can vary in accordance to circumstances.

Question 3

Lacking Validity (capacity)

Answer 3

Jacobs’ study was conducted a long time ago. This means that it lacked adequate control. e.g. ppts may have been distracted while they were being tested so they didn’t perform as well as they might. So this is confounding variable. Limitation because this study lacks internal validity. However results of this stud have been confirmed in other research so it may still have its validity.

Question 4

Not so many chunks (capacity)

Answer 4

Miller overestimated the capacity of STM. For example Cowan reviewed other research and concluded that the capacity of STM was only about four chunks. Limitation because suggests that lower end of Miller’s estimate (five items) is more appropriate than seven items.

Question 5

Artificial stimuli in STM study (duration)

Answer 5

In P and P study the stimulus was artificial. They had to memorise consonant syllable which do not reflect real life activities where we might try to remember more meaningful things. So study lacks external validity.

Question 6

High external validity (duration)

Answer 6

Bahrick’s study had higher external validity than other research conducted into STM and LTM. He studied meaningful activities such as pictures. Shepherd found that when studies into LTM used less meaningful stimuli recall rates were lower. So study has high external validity. However a limitation of Bahrick’s study is that confounding variables were not controlled such as the ppts looking at the yearbook photo and rehearsed their memory over the years so more likely to remember.