The decisive shift from object to operation replaces resemblance with mechanism as the basis of transdisciplinary comparison. Duchamp demonstrates that an object's status can change through selection, displacement and institutional framing without any alteration to its material substance; Bateson relocates explanation in circuits of relation and feedback; Lefebvre understands space as something continually produced through practices, representations, property and use; Latour distributes action across heterogeneous assemblages of people, documents, technologies and material objects. Together they establish that things become analytically significant through the transformations they produce. A wall regulates heat, sound, sight and movement; a zoning designation redistributes development pressure; a bench organises posture and sociability; an interface structures choice; a tree modifies shade, humidity and habitat; an archive enables claims to return to present action. This operational perspective avoids the weakness of generic relational language because it demands a specific answer to the question: what changes? Relation becomes analytically useful only when it can identify a threshold, redistribution, classification, feedback loop, persistence mechanism, exposure or alteration of access. This also provides a rigorous foundation for comparison across heterogeneous fields. A building and a database are not comparable because both can metaphorically be called systems; they become comparable when each can be shown to regulate admission, visibility, memory or circulation through identifiable mechanisms. Transdisciplinarity therefore becomes exact when difference between objects is preserved while operations become comparable. Its elementary unit is not the isolated thing but the transformation a thing makes possible within a wider field.