Effectiveness is how well something achieves its purpose. Measure effectiveness, cost-effectiveness, the effectiveness of the drug.
It is distinct from efficacy in medicine, which is a real and useful split: efficacy is how well a treatment works in a trial and effectiveness is how well it works in ordinary life, where people forget doses. Cost-effectiveness weighs the result against the price. Note effective, from the Latin for accomplishing.
1nouneffectivenessHow well something achieves its purpose.
“Doctors are testing the effectiveness of the new vaccine.”
effectiveness is a measure of success.
French
effectif
English
effective
English, today
effectiveness
Built from
From effective + -ness. effective comes from French effectif. From French effectif, from Latin effectīvus (“productive; effective”), from efficiō (“to make; to bring about”), equivalent to effect + -ive.
Etymology from Wiktionary, CC BY-SA