In A Singular Opportunity for Health Interoperability I summarized a metaphor based on the Web standards HTTP and HTML which was “get HL7 and other SDOs out of the HTTP business.”
Metaphors gain their power from poetic ambiguity. One of the great things about a metaphor is that it can rally so many folks to believe they agree. They each read the metaphor as supporting their favorite point. The follow-on to a metaphoric rally must be a drill-down to tease out where the metaphor singles out an important common cause and where it papers over differences. Using a RESTful approach to interoperability is another metaphor. Some of the discussants take it quite literally as the single most important point to agree on; others see RESTful as an example of a broad approach to rapid innovation.
Over the last few days I have come to believe the following “big takes” on this discussion. In another simplification I break the discussants into two groups, “the Internet crowd” and “the healthcare informatics crowd.” I mean no disrespect to either group and understand that many people have a foot in both camps or at least a foot in one and a toe in the other.
There are implicitly three levels of contention. I will arbitrarily assign them to a vertical stack.
Bottom: Connecting (in the broadest sense). So much has been accomplished with well-layered Internet protocols to create quite complex behaviors and progress has progressed so rapidly that “the Internet crowd” can’t understand why “the healthcare IT crowd” wants to stick to technologies for secure transport that are “so five years ago” but preclude participating in rapid evolution. “RESTful operations” are a token of the deeper conflict, not the actual point of contention. Some of the informatics crowd significantly confuses the issue by presenting discussions on security based on standardized roles and other as yet unproven constructs.
Top: Semantics of Data. Understanding data clearly is a never-ending task. As Bertrand Russell said “Everything is vague to a degree you do not realize till you have tried to make it precise.” The Internet crowd has done very well with a model where semantics evolve as rapidly with experience. They have productivity tools that rely on some unstated but “common sense” approaches such as using business names as XML element names. The health IT crowd has been through this learning curve on clinical data and wants to skip over many learning steps that uncover ambiguities on health data. However the health IT crowd (including HL7) has made it more difficult to propagate its knowledge about health data because they have chosen to package it in self-created modeling formalisms and XML that is obscure to the max and doesn’t work well with common XML tools. They further complicate the issue by not knowing how to package their sophisticated understanding in a way that it can be understood by programmers who know the data of their own application but don’t comprehend the abstract approach.
Middle: The Semantics of Exchange Sequences. To a certain extent saying something is “architecturally neutral” means “it isn’t interoperable in any architecture.”Any attempt to truly achieve interoperability involves a state machine that implies certain sequences of transactions needed to get the job done.
The Internet crowd is used to improvising the sequences of actions that are required to accomplish a task but not standardizing them. The health IT crowd has attempted to establish very loose architectures (i.e., no technology or system factoring constraints) that standardize the sequences enough that two products that are expected to be interoperable could interoperate without continually adjusting the code based on what is going on in the broader community. Thus the Healthcare IT has fought its way to largely agreeing on XDS over a five year period (and XDS has evolved in that period) and the Internet crowd sees XDS as not applicable to their use cases and restricting their ability to improvise.
The Internet crowd represents a culture that employs the power of the Internet protocols in an enterprising, high-energy, innovative and incremental approach that has revolutionized some industries. The informatics crowd really does have the ability to shortcut many learning cycles based on experience and understanding. How can we introduce combine the peanut butter with the chocolate? Oops! There goes anothe r metaphor.