A cognitive psychologist is planning an experiment to investigate the effect of sleep duration on cognitive performance. Participants are randomly allocated to either a restricted sleep group (4 hours of sleep) or a normal sleep group (8 hours of sleep). Reaction times (in milliseconds) are then measured using a computerised test.
Which of the following statements represents a correctly formulated directional (one-tailed) hypothesis for this study?
There will be a significant difference in reaction times on the computerised test between participants in the restricted sleep group and those in the normal sleep group.
There will be a significant correlation between the number of hours of sleep a participant receives and their reaction time on the computerised test.
Participants in the restricted sleep group will have significantly slower reaction times on the computerised test than participants in the normal sleep group.
There will be no significant difference in reaction times on the computerised test between the restricted sleep group and the normal sleep group.
