A memory study with a 2 (type of instruction) × 2 (presentation rate) factorial, like the example used at the start of the chapter, has these results (DV = words recalled): Imagery/2-sec rate = 20 words Imagery/4-sec rate = 20 words Rote/2-sec rate = 12 words Rote/4-sec rate = 12 words Are there any apparent main effects here? If so, for which factor? or both? Calculate the row and column means.