A friend of mine and I are arguing over the origin of the word ‘parametric’ as in ‘parametric design’.
While my friend thinks it’s from ‘parametric’ as in ‘input parameter of function(method)’, I think it derives from ‘parametric’ as in ‘parametric representation’ or ‘parametric equation’.

Which is correct? (I would much appreciate of you can provide with some proofs too.)

Surely you are arguing over meaning, not origin? One parametric does not originate from another, it is simply one and the same word.

According to my ancient paper-based OED “parametric” is an adjective meaning of, relating to or expressed in terms of a parameter or parameters.

Common sense would suggest that parametric design is design that produces a product by applying a set of rules to a set of parameters such that changing the value of a parameter will result in a change to the output product. Possibly predictably. but perhaps sometimes with conscious randomization.

So, as design is an active process, my vote would be for “expressed in” rather than “of” or “relating to”.

Parametric equation comes from parametric the same way parametric design does. It is an equation which has parameters Like design which uses parameters. I believe the use of parameters would be the origin for both.

Thank you Jeremy. Pardon my limited English, what I meant to ask was why is it at all called ‘parametric design’ in the first place and why not called else wise for instance algorithmic design or computational design?

I believe the term parametric gained architectural relevance during the “first digital turn” when architects started appropriating tools from other industries such as mesh and NURBS 3d modellers.

In a similar way of appropriating the tools, architects appropriated the terminology to describe design by parameters and began embodying a new set of values eventually explicitly defined as a new “style” of architecture : parametricism coined by Patrik Schumacher from ZHA in his essays and books.