A cognitive psychologist wanted to investigate whether there was a relationship between habitual sleep duration and executive functioning, measured via a Stroop color-word interference task.
An advertisement was posted on a popular online forum dedicated to sleep optimization, SomnoOptimise, asking for adults aged 18 to 35 to participate. Eight participants volunteered for the study. They tracked and reported their average sleep duration (in hours per night) over a one-week period and then completed a laboratory-based Stroop task (with a maximum executive function score of 50).
The results of the study are shown in Table 1 below.
| Participant | Sleep duration (hours) | Stroop task score /50 |
|---|---|---|
| A | 6.2 | 38 |
| B | 4.5 | 29 |
| C | 8.1 | 45 |
| D | 5.0 | 32 |
| E | 7.4 | 41 |
| F | 5.8 | 35 |
| G | 6.9 | 39 |
| H | 8.5 | 47 |
Explain one limitation of the sampling technique used for this investigation.
Practise Edexcel A Level Psychology Research methods and skills with exam-style questions for A Level Psychology. 657 questions covering Research methods and skills, matched to the Edexcel A Level Psychology (9PS0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
