I add resilience/adaptiveness... the ability to respond productively to changes in the environment.

Thanks Patrick. An important addition.

I once ask (on ask metafilter) "what's the difference between efficiency and effectiveness". Here is one answer I got : "Effectiveness is comparing information from several dictionaries to determine the best answer. Efficiency is using AskMefites to do the work for you."

I like to clearly differentiate between effectiveness and efficiency. I think of effectiveness as "doing the right thing," whereas efficiency is "doing something well." Focus on effectiveness first, then on reliability, then efficiency.

p.s. Your TypeKey authorization is out of whack.

Hi Jack

I posted Tom's description because I have experienced the efficiency v effectiveness debate as being very vexed for very long. I found that thinking of efficiency as a subset of effectiveness resonated with me. It makes sense in my mental frameworks and I can use it to communicate the difference between the two concepts (IMHO).

Your contrast between 'doing the right thing' and 'doing something well' has caused me to take stock. And on reflection I think about effectiveness as being both those things. I can't get away from efficiency as having a more limited focus on resources (applying sufficient resources to get the job done, but no more).

In writing this I am conscious of the assumptions underpinning my association of 'efficiency' with 'resources' and of our possible different interpretations of the word 'well' (from your phrase 'doing things well').

Here is my favorite acedote on misplace efficiency:

"…He was also a longtime student of the military, and one day he told me a story. Years before, he said, a bright, forward-thinking German general divided his officers into four classes; the clever, the stupid, the industrious, and the lazy. The general believed that every officer possessed two of these qualities. The clever and lazy, for example, were suited for command (they’d figure out the easiest way to do a task); the clever and industrious were suited for high-level staff. The lazy and stupid, he maintained, were an unfortunate by-product of any system and could be slotted in somewhere; but the stupid and industrious were just too dangerous, and the general’s standing order was to have them removed from the military completely, the moment they were identified."
"About Face", pp.347
Hackworth, David H., Sherman, Julie. (1989). About Face. New York. Simon and Shuster.