Peter Drucker once defined the difference between efficiency and effectiveness as follows:
Efficiency is doing the job right. Effectivenees is doing the right job right.
Jeffrey Phillips, over at Thinking Faster, posts this entry "Doing fast things or doing things fast?" in which he looks at the differences between efficiency and effectiveness.
"Do we place too much emphasis on efficiency and not enough on effectiveness? To me, the difference between the two is that efficiency is doing a task with the least amount of effort required to complete it, while effectiveness is doing the right job at the right time with the right amount of resources. Too often I think we opt for efficiency rather than effectiveness."
BOTTOMLINE: "We should evaluate each task and determine - am I working on fast things or working things fast? If the former, that's ok. Some tasks and work can be worked quickly to completion. If you are working things fast, you are probably not living up to expectations down the line from you. One goal is speed, but other goals include accuracy and completeness. Don't assume efficiency is all that is required."