In a sense those are all finer grained extensions of the same concept: How hard it is to reason about the code. On the highest level are easily quantifiable things like wrapping several error producing segments in a single try / catch block, obscuring the source of an error. Use of interfaces makes documentation and refactoring easy. Then the lowest level stuff is pure style -- much more subjective, but meaningful in a team environment. When people write code in the same style, you spend less time parsing style differences and more times parsing the actual semantics.