I've got two buttons the user will click to indicate whether a stimulus is the same or different
Currently I'm using = (U+003D) and ≠ (U+2260, = with a diagonal line through it).
Is there a more universal icons/symbol for that?
I'm convinced these are the only universal symbols. There are no other similar symbols in Unicode. I.e. any other symbol with the same meaning is so obscure that it doesn't even occur in Unicode. There is ≡
(U+2261) identical and ≢
(U+2262) not identical, but those are understood to be variants of = and ≠.
==
for SAME and!=
for DIFFERENT