Paper describing the differences between dogs and cats: "Compare/contrast organization" ; This is because you are comparing and contrasting between cats and dogs.
Paper explaining the path of the Oregon Trail: "Spatial organization"; This is since you are placing the locations and sites in order according to the path of the Oregon Trail.
Paper covering the timeline of Shakespeare's play: "Chronological Organization"; Due to the fact that you are placing each timeline according to the start date and to the end date.
Paper showing the major reasons for the Civil War, followed by lesser reasons: "Order of importance".; Since the paper lists what is important before the less important reasons of the Civil War.
So, your order would look like:
Spatial organization: 2
Order of importance: 4
Compare/contrast: 1 (just like how you have put)
Chronological: 3
Let me know if you need further info. :)
- Dotz