When is it appropriate to use a biased opinion in a research paper? it is never appropriate. when you supply both sides for a complete picture when you use one side to strengthen your thesis's claim there is never a time when a biased opinion is inappropriate to use.

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.