Definitions of interoperability surround us, but all the attention in the world to definitions make very little difference in the end.
What is your theory of interoperability? How would you test it?
My theory of Interoperabilty: Starts with a desired outcome that has a known value. Without this use-case driving interoperability you are just talking technical capabilities. Meaning, the reason why one can get PDF out of WORD, but not PDF into WORD, is because the desired outcome with a known value is to produce a report that can be rendered easily but not modified easily. Hence this is a delivered Interoperability.
In healthcare, I fully understand why a Patient would want to enable a specialist to gain full access to their medical history. A understood outcome with a known value. This is why I very much support and work hard to enable providers to communicate in as full fidelity as possible, while also enabling Patients to control that communication flow (Privacy Consent). See In Wisconsin we have Interoperability
While I am really not a fan of mechanisms that put the Patient as the means of communications. I understand that this could be the least common denominator, but why try to improve in such a undesireable way. This said, we do have the Meaningful Use feature of "Download". In fact my healthcare provider has provided this for a very long time, and I have downloaded my data. I have a copy of my data, in XDM.zip form of both PDF and CDA. So I have in my hands what, as healthcare standards geek, understand as the most highly interoperable form possible. YET, I have no clue what to do with this data. Why do I have it? Why do I need it? See I feel BlueButton advancement
yes, I know that I am lucky to be in good enough health that I 'don't need it'... and I feel for anyone that really does need it and can't get it.... This is why I continue to work on solutions that don't make practical sense to me personally.
Interoperability delivers a desired outcome that has a known value.