An objectified fact type that involves two or more participants is recognised as a relationship between them. One that involves a single participant is not: it falls back to being classified as an independent type.

These single participant cases are common. A valuation, a preference, a rating or an opinion expressed by one party about something else is an aspect of that party, not a thing that stands on its own. Classifying it as an independent type hides where it belongs and what it depends on.

Expected: an objectified fact type identified through a single other type is classified as an aspect of that type.