It has been a time honored caveat that Scandinavians used a patronymic naming system. Yes and No. I have both Norwegian and Swedish surnames in my family file.
My Swedish Peterson/Neilson line appears to have followed the standard naming convention. When I found the marriage record of Leopold Peterson and Caroline Neilson the parents names were listed as Peter and Anne for Leopold and Nils and Karna for Caroline. Peter who? Last names would have been helpful, but at least I know the naming pattern that was used.
My Norwegian Hansen/Danielsen ancestors however, freely changed from the patronymic to using the last name of the father. My grandfather, Adolph Hansen, was christened under the name Adolph Johannesen. His father was variously recorded as Johannes Hansen and Adolph Hansen. My great-grandmother, Dorette Christiansdatter, was also named as Dorette Danielsdatter and her brother became Oskar Daniels. Their father was Daniel Christians.
Since this is Surname Saturday, I won't begin to talk about the first name changes. At least they kept their ages consistent.