"When a specific desired end is attained we shall say that the action is "effective." When the unsought consequences of the action are more important than the attainment of the desired end and are dissatisfactory, effective action, we shall say, is "inefficient." When the unsought consequences are unimportant or trivial, the action is "efficient."
Effectiveness or effectivity is the capability of producing a desired result or the ability to produce desired output. When something is deemed effective, it means it has an intended or expected outcome, or produces a deep, vivid impression.
"The executive is, first of all, expected to get the right things done. And this is simply saying that he is expected to be effective […] For manual work, we need only efficiency; that is, the ability to do things right rather than the ability to get the right things done. The manual worker can always be judged in terms of the quantity and quality of a definable and discrete output, such as a pair of shoes"
"Effectiveness relates to the accomplishment of the cooperative purpose which is social and non-personal in character. Efficiency relates to the satisfaction of individual motives and is personal in character."
"The effectiveness to be aimed at calls for the application and refinement of all conceivable prognostic techniques for adding to knowledge of the future, including those which can be effectively developed over an ever-wider time scale."
"Truth is great and its effectiveness endures."
"Besides each one of us working individually, all of us have got to work together. We cannot possibly do our best work as a nation unless all of us know how to act in combination as well as how to act each individually for himself. The acting in combination can take many forms, but of course its most effective form must be when it comes in the shape of law — that is, of action by the community as a whole through the lawmaking body."
"A business of high principle generates greater drive and effectiveness because people know that they can do the right thing decisively and with confidence."