In a laboratory experiment investigating the effects of screen blue-light filters on cognitive performance, researchers recruited 15 young children (aged 6 to 8) from a single primary school to complete a 5-minute spatial rotation puzzle on a tablet, under either a standard high-intensity screen setting or a blue-light filtered 'warm' screen setting. Performance was measured by the total time taken (in seconds) to complete the puzzle.
Explain two improvements that the researchers could make to this study.
Practise Edexcel A Level Psychology Methods with exam-style questions for A Level Psychology. 638 questions, 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.