How could they be anything other than linear?

To me a linear scale should be 0 to 10.
A scale of 1 to 10 suggests logarithmic, in which case the midpoint is a little over 3.

I know that’s not what most people have in mind—using 1 instead of 0 as the lower end-point of an intended linear scale is a sign of innumeracy (which of course afflicts most of the population). Imagine measuring length with a ruler that begins at 1 inch!

I think of them as linear like points on a ruler.

I think of it in terms of the statistical normal distribution curve. A 5 is average, and 0 and 10 are almost unheard of. The majority fall between 3 and 7, so a 2 is exceptionally bad, and an 8 is exceptionally good.

@FireMadeFlesh Yes, but on a scale of 1–10 a normal distribution would have an average of 5.5, not 5.

When we rate things on some kind of scale, it’s fundamentally an act of measurement, not counting. Therein lies the difference between starting with zero instead of 1.

@gasman I totally agree. That’s why I said “0 and 10 are almost unheard of” – I include 0 in my scale, but like 10 it is never used, because the tail is vanishingly small at that point.