What is the level of measurement / name of the scale of list-features?
With a list such as this list of authors, the only representation which truly capture the semantics is a (long) list of boolean features, one for each possible author in the set. Ideally one would also pre-process the whole set of authors in order to match the different ways a name can be written, e.g. "J. Doe" = "John Doe" = "Doe, John".