Think about how the authors structure their article. why is this structure effective?

answer: they are asking about the format in which the artivle is written

explanation: eg; the font, choice of language etc.

you need to include the text. we have no idea what you are referring to

type of error:

the error in the sentence is a "dangling modifier". a dangling modifier is a phrase, word or clause that "dangles" because there is not target to modify. in this case, "after mopping the floor" is the dangling modifier since it has no word to modify. the noun "house" cannot mop the floor; therefore there is a mistake in the writing of the sentence.