How does direct realism differ from the view that people perceive sense data?

In the context of philosophy, the distinction between direct realism and the theory of sense data centers on what an individual immediately apprehends during perception.1

The Sense-Data View

The theory of sense data posits that human beings are never directly aware of physical objects themselves. Instead, when we perceive the world, we are directly aware of "sense data"—private, mental entities or appearances (such as the elliptical image of a round coin viewed from an angle). Because these sense data are considered mind-dependent and private, this view faces the "egocentric predicament": the challenge of justifying how we can infer the existence of an external, public world from these internal, subjective experiences.123

Direct Realism

In contrast, direct (or “naive”) realism asserts that physical objects themselves are the direct objects of perception. Under this view, there is no need to infer the existence of the external world from mental intermediaries because we perceive the physical objects (or their surfaces) immediately. While some direct realists attempt to redefine sense data as physical parts of an object, others reject the concept entirely, arguing that we observe the physical environment directly.1