estimand

Apparently of mid-20th century coinage from Latin aestimandum, gerundive of aestimo (“I value", "I estimate”).

estimand (plural estimands)

1. (statistics) that which is being estimated.
   • 1939, CF Roos; V von Szeliski, “The Concept of Demand and Price Elasticity--The Dynamics of Automobile Demand”, in Journal of the American Statistical Association:

     Statistics needs a term like estimand to replace the ...

   • 1968, Frederick Mosteller; John W. Tukey, “Data Analysis--Including Statistics”, in Handbook of Social Psychology: Research Methods, page 106:

     We speak of the estimator's target as an estimand (as something to be estimated) rather than just as a parameter.

• Danteism, mediants, tidesman