Cognitive practical - how is memory encoded in STM?

Aim?

To investigate how STM is encoded, based on acoustic encoding.

Procedure?

4 participants chosen in an opportunity sample as I used family members. An independent groups design was used as each participant was only used once and in one condition. I used a pre-prepared slideshow with a list of words. I sorted my participants into 2 conditions:

• condition A: list of 10 acoustically similar words

• condition B: list of 10 acoustically dissimilar words

I presented the words to participants for 3 seconds per word, with the words in the same colour and font. I then asked participants to recall the words in the correct order. I gave them a list of the words in a randomised order to aid them.

Findings?

Participants recalled significantly more acoustically dissimilar words than acoustically similar words, allowing me to accept the alternative hypothesis.

Weakness?

The participants were tested in different environments - it was not consistent. Due to limitations of resources, some participants had to be tested in noisy, public environments whilst some had silent rooms. So, extraneous variables, such as noise, may have affected concentration of my participants and therefore their recall of the words. This lack of control decreases the internal validity of my study as other factors may have impacted the dependent variable (words recalled) other than the independent variable (the condition).

Strength?

My study had a standardised procedure - all of the participants were given the same written instructions, resources were standardised, each word was shown for 3 seconds, etc. Furthermore, the words chosen in each condition were all equally common in the English language so potential extraneous variables of familiarity were eliminated. This high degree of control means that my study can be considered to have a high level of validity.

Improvement?

To improvise, I would conduct my study in the same room for each participant (eg- a quiet library), to ensure each participant has the same experience and eliminate the affect of noise which may have affected participant concentration. This would mean that the only influence on participant recall would be the condition as opposed to extraneous variables, such as environment.