DEMENT AND KLIETMAN EVALUATION Flashcards
Strengths- overall
High level of control
Internal Validity (ppt v, revised procedure, operational)
Objective measures/results
Strengths- internal validity
- ppts found it too difficult to estimate dream length so 2 fixed options were introduced (15/5)
- clear operational dream definition. Reports were not counted if they had a vague impression of dream/no specific details.
-ppts variables reduced (ability to estimate
= minimises confounding variables. Causal relationship between REM and dreaming.
Strengths- objective measures
- use of EEGs/EOGs that recorded brain waves and eye movement patterns.
- electrodes were placed consistency producing similar info.
= biological precise measures with no research bias (reliable). Produces quantitative data easy to collect/analyse. Mitigates limitations of subjective self report.
Strengths- high level of control/ standardise procedures.
- not allowed to drink caffeine / alcohol before experiment.
- ppts were all awaken with a doorbell.
- limited contact between experiment and ppts during dream recall.
- sleep environment was regulated to be quite/dark .
Why were ppts not allowed to drink caffeine /alcohol before the study?
Caffeine- A stimulant that can interfere with the ability to fall asleep/disrupt sleep cycle.
Alcohol- A sedative that can contribute to less restorative sleep/ disrupt sleep cycle.
= wouldn’t reflect natural sleep pattern
Why were all ppts woken with a doorbell?
Instantly wake up
Dreams wouldn’t be forgotten by slow- woken ppl.
Why was sleep environment was regulated to be quite/dark ?
Simulate natural, familiar sleep environment
Why was there limited contact between the ppts and experimenter during dream recall?
Minimise research bias
Weakness- ecological validity (mundane realism)
- not in usual sleep setting
- artificial lab, connected to machines (anxiety)
- may have been used to drinking alcohol/coffee thus produce a typical dreams.
- ppts were woken several times during the night and asked questions
Weakness- Generalisability
- small sample (9 ppts) results may have been individual
- 7 males/ 2 females (gender bias)
- Possible sample bias- volunteer sample. Could have attracted ppl with visual dreams.
- relationship between dream content eye movement patterns could vary from person to person. Conclusions could have been strengthen if the same relationship were eatables in a larger sample of ppl.
Difficult to generalise results to wider population.
Weakness- subjective self reports
- ppts reports of dream content was subjective and dependent on how expressive they were.
- self reported dreaming experiences can be prone to recall bias, inaccuracies.
= lowers internal validity
How were the ethics?
- informed consent not gained (not told about their EEG/ which sleep stage they were in/ eye movement patterns
- well being concerns. Sleep vital for health, cognitive function. Ppts might not be fully aware of consequences of sleep interruptions
Why is having a high level of control good?
Internal validity?
