The linked document seems pretty clearly addressed to both teachers and students, which might not be a great decision. If they had an entry point dedicated only to students they could probably leave out all the places where they mention pedagogy. That said, I think it’s a bit of a stretch to criticize “pedagogy” as being a complicated term. It’s okay to occasionally need to look up something in a dictionary, especially in cases like this where it’s an incredibly precise and standard word for the concept it’s referring to. You could also find and replace all mentions of “biology” with “the study of life,” but I think using these terms are fine even if a very small portion of readers need to look it up once in the dictionary.