 Sense-datum theorists divide over exactly how to understand sense-data insofar as they are non-ordinary. Some early sense-datum theorists (such as Moore) initially took sense-data to be mind-independent, but peculiar non-physical objects. Later theorists treat sense-data as mind-dependent entities (Robinson (1994)). This is how the theory tends to be understood in literature from second half of the 20th century on. 