Study Edexcel Psychology research-design questions by improving sampling, procedures and controls so investigations become more representative and credible.
Louis investigated the effect of sleep disturbance on appetite. He conducted his investigation using nine rats. Louis set an alarm bell to ring at fixed one hour intervals over a ten-day period to disturb the rats.
Louis provided 25 grams of food to each rat at 09:00hrs each day. He recorded the amount of food remaining at 19:00hrs when he removed the food from the cage.
A control group of four rats that were not deprived of sleep were used as a comparison for his results.
Explain two improvements that Louis could make to his investigation about the effects of sleep disturbance on appetite in rats.
2
AO2 (2 marks), AO3 (2 marks)
Credit one mark for accurate identification of each improvement in
relation to scenario (AO2)
Credit one mark for exemplification/justification of each improvement
(AO3)
For example;
- Louis could set the disturbance buzzer to go off every ten minutes
to make sure the rats do not sleep for an hour (1). This would
increase the reliability of any findings that sleep disturbances did
affect the appetite of the rats (1)
- The study could be conducted during the night instead of the day
time as rats are nocturnal (1). This would increase the validity of
the experiment as the appetite of the rats would be measured in a
more normal context (1).
Look for other reasonable marking points.
Generic answers score 0 marks.
(4)