Can two different data standards be syntactically interoperable but not semantically interoperable?

• A. No
• B. It depends on the context
• C. It is impossible in healthcare
• D. Yes

Answer: (D)

Syntactic interoperability is about the ability to exchange data in a shared structure and format so the information can be parsed and stored. Semantic interoperability goes deeper: it requires that the meaning of every data element, code, and value is understood in the same way across systems.

Two data standards can line up on structure, encoding, and message syntax so data can be transmitted and parsed without errors. But if they use different vocabularies, coding systems, or unit definitions, the same data element may be interpreted differently. For example, one standard might encode a diagnosis with ICD-10-CM codes, while another uses SNOMED CT; without precise mapping between those vocabularies, a code can be parsed correctly but convey a different clinical concept. Likewise, lab results could be expressed in different units (mg/dL vs mmol/L) or use different value ranges, so even a correctly parsed value can be misinterpreted.

Because of these semantics gaps, data can be syntactically interoperable yet not semantically interoperable. That’s why semantic alignment—shared vocabularies, mappings, and standardized value sets—is essential for true interoperability.