Somewhat disappointed at this failure to impress modern youth, I tried again at the weekend with his Putonghua teacher. She was delighted with the educational possibilities of this new tool, and I was happy that technical advances are still appreciated by an older generation. Then she peered more closely and complained: "But the cars aren't moving."

Why do non-technical people have such unreasonable expectations, I wonder?

Thanks to the efforts of Vietnam War-era computing pioneers, we are approaching 40 years of systems "interoperability". Unfortunately, their early declaration of "mission accomplished" in relation to interoperability seems to have been forgotten. Every decade or so, it seems, a new set of enthusiasts demand better interoperability and, in response to this reasonable request, various governments publish anew their updated frameworks for interoperability.

In the banking world, our test of reasonableness has generally been less to do with technical interoperability and more with the issue of trust between parties. Like many others in Hong Kong, I have deposited a check drawn on the UK branch of a very large local bank and been shocked to hear that it will take at least four weeks for the check to clear. This level of mistrust of their fellow bankers in the same organization has always seemed unreasonable to me and led me to suspect an ulterior financial motive for such degraded interoperability.

But banks aren't the only local retail financial organizations. One well known Hong Kong institution enjoys a reputation for "knowing its customers" and establishing trusted channels for them, especially higher value financial transactions. In the early 90s, they also discovered the difference between marketing brochure claims about "interoperability" and vendors' beliefs about reasonable interpretation of these claims in actual performance of supplied systems.