An experiment was done to look at the positive arousing effects of imagery on different people. A sample of statistics lecturers was compared against a group of students. Both groups received presentations of positive images (e. g., cats and bunnies), neutral images (e. g., duvets and light bulbs), and negative images (e. g., corpses and vivisection photographs). Positive arousal was measured physiologically (high values indicate positive arousal) both before and after each batch of images. The order in which participants saw the batches of positive, neutral and negative images was randomized to avoid order effects. It was hypothesized that positive images would increase positive arousal, negative images would reduce positive arousal and that neutral images would have no effect. Differences between the subject groups (lecturers and students) were not expected. What technique should be used to analyse these data? Three-way mixed ANOVA Two-way mixed ANOVA Three-way repeated-measures ANOVA Two-way mixed analysis of covariance