Effectiveness and efficiency act against one another, and may be key drivers in design.
The definition of effectiveness is weak. We need a better definition. Some alternatives include:
Some of the definitions indicate that effectiveness is a quality, not a quantity. Clearly, there is no standard measure of effectiveness (as there is for efficiency).
HERE ⇒ What is known about measuring effectiveness?
There's a difference (in medicine) between efficacy and effectiveness. Per 1, efficacy refers to how well an intervention works in subjects who receive it, whereas effectiveness refers to the evaluation of an intervention in subjects to whom the intervention is offered. The difference between efficacy trials and effectiveness trials is compliance.
In [AEO11]: “…the nature of [ecology] is often misunderstood. Simply maximizing efficiency in the use of resources is helpful in the short term but ultimately ineffective where a resource is finite and non-renewable. The resource will eventually run out and no amount of efficiency will sustain effectiveness.
Typically, systems are optimized for efficiency without (properly) considering effectiveness. There is significant evidence for this in the literature.
Optimality is always relative. The optimum (best, most efficient) solution is always measured relatively too. Usually with respect to energy consumption or cost.
To be optimal in one context, means that the solution is (usually very) suboptimal in other contexts. So as conditions change, the highly optimal solution becomes brittle and loses optimality quickly.
Now consider looking at how efficiency changes for the same thing over multiple contexts. If one found a level of optimality that was the highest common possible value over the range of contexts, then one would have a suboptimal solution in any one context, but a maximally optimal solution in a broader range of contexts.
(useful output)/(all inputs + all useless outputs)?