In "The Raven" By Edgar Allan Poe, Rhyme scheme is the device that plays a larger role. He uses it when he says, "Once upon a midnight dreary, while I pondered, weak and weary." It plays a large role because you can hear the rhyme scheme while your reading it.
In "The incident in the Rose Garden" By Donald Justice, imagery is the device that plays a larger role. He uses it when he says, "A little cage of bone." It plays a larger role because it uses it to describe things like he was describing his hand.