Incomplete comparisons detract from the clarity of your writing. To be complete, a comparison must include both the item being compared and the item it is being compared with. If you leave out the item being compared with, the reader may not understand your intended meaning.
Ecological modeling is more difficult.
[More difficult than what?]
Ecological modeling is more difficult than hydrological
modeling.
--Norman Boucher, "Back to the Everglades," Technology Review (modified)
Ever since the early 1960s, when the Corps of Engineers completed the
Central and Southern Florida Flood Control Project, the area's fresh water has
been shunted through 1,400 miles of canals and levees, 150 gates and spillways,
and 16 of the largest pumping stations.
[Largest where? In the project? In the area?]
Ever since the early 1960s, when the Corps of Engineers completed the
Central and Southern Florida Flood Control Project, the area's fresh water has
been shunted through 1,400 miles of canals and levees, 150 gates and spillways,
and 16 of the largest pumping stations in the world.
--Norman Boucher, "Back to the Everglades," Technology Review (modified)
