How do antirealists distinguish between observable objects and unobservable entities?

In the philosophy of science, antirealists distinguish between observable objects and unobservable entities by emphasizing that the primary goal of science is to achieve "empirical adequacy" rather than a literal description of reality.12

Antirealists, such as proponents of constructive empiricism, argue that scientific theories should be evaluated based on their ability to "save the phenomena"—meaning they must correctly predict and account for observable facts and experimental results. From this perspective:12

• Observable objects: These are entities or states of affairs that can be directly perceived or recorded through observation. Antirealists maintain that statements about these objects can be true or false based on observable evidence.1
• Unobservable entities: These are theoretical constructs (such as subatomic particles or atoms) that are not directly accessible to human perception. Antirealists argue that scientists need not commit to the actual existence of these entities; instead, they view them as useful tools or instruments for generating predictions about the observable world.132

While realists often challenge this distinction by arguing that there is no "theory-neutral" language to separate the two, antirealists maintain that a principled difference exists between observing an object, such as a jet airplane, and merely observing the effects of an unobservable entity, such as a particle trace in a cloud chamber.1