Someone pointed out that many people use "parameters" to mean "perimeters." Here is what I found about that confusion.

Now I am wondering if I use the word "parameters" correctly. If you talk about the "parameters" of a project, meaning the limits of the project, is that correct? I would surely not say "the perimeters" of a project. How are those 2 words confused? I am not clear on that.

About 15 years ago a couple of professors I had known in Taiwan advised me that they were returning home to Ohio and might stop in Hawaii. I wrote back, inviting them to visit. They then said they wondered about "the parameters."

Unsure as to the meaning, I (evasively) answered thusly:

You'll want to see the gardens, zoologic and botanical,
And lava flows, both cold and hot, of origin volcanical.
You'll get to talk with experts, professionals and amateurs,
Who'll answer all your questions with regard to the parameters.

I haven't encountered this usage in the wild, only in discussion of it. Neither is quite natural for me, but it's a fairly natural extension or metaphor from either word. I don't think you can clearly say it's meant to be one or the other.

Technically, the perimeter is the edge or outer circuit of a plane figure. So the perimeter of a rectangle is the length of all four sides added together. By extension the perimeter of an army base is the whole length of its walls or borders, which you would inspect on guard duty. Strictly perimeter is singular. But then it comes to be used as plural: the perimeters of an army base are its edges, its borders, or the regions out at the edge.

Now a parameter is a bit harder to characterize in non-technical language. It's a variable that changes something else if you change it. The parameters of a rectangle are its length and its width. If one of those changes, the exact nature of the rectangle does. So the 'parameters' of an experimental situation -- say how fast and how high an aeroplane can go given a certain amount of fuel and/or weight and/or wing shape -- are how much the situation can vary, the limits of the situation.

In this way we get two unconnected words, parameter and perimeter, both meaning 'limit(s)', by a fairly straightforward extension. As to a project: under which metaphor are we conceiving it? I think it could be either.

Unsure as to the meaning, I (evasively) answered thusly

A little cross-threading again, right, Jerry?

Aput, thanks for that clear distinction between the 2 words. I am certain that I have used the word "perimeter" correctly, but I suspect I haven't used "parameters" correctly. As that site indicated, the term "parameters" is a good example of 'scientific puffery,' and I probably have been guilty of using it that way.

Jerry - you are marvelous! I sang right along - I love Pirates of Penzance!