Prototyping significantly reduces requirements and design errors, especially for user errors.
A caveat is that prototypes are about 10% of the size of the planned system.
This leads to the conclusion that large systems are best done using incremental development if possible.
Author : Barry Boehm
Adding people to a late software project makes it later.
For small projects with less than five team members, adding one more experienced person will not stretch the schedule, but adding a novice will.
Author : Fred Brooks
There are only two hard things in Computer Science: cache invalidation and naming things.
Author : Phil Karlton (not confirmed)