 For example, she said that nobody taught Koko the word for "ring", but to refer to it, Koko combined the words "finger" and "bracelet", hence "finger-bracelet".Criticism from some scientists centered on the fact that while publications often appeared in the popular press about Koko, scientific publications with substantial data were fewer in number.Other researchers argued that Koko did not understand the meaning behind what she was doing and learned to complete the signs simply because the researchers rewarded her for doing so (indicating that her actions were the product of operant conditioning).