摘要: Despite years of work, no re-usable clinical terminology has yet been demonstrated in widespread use. This paper puts forward ten reasons why developing such terminologies is hard. All stem from underestimating the change entailed using software for ‘patient centred’ systems rather than its traditional functions statistical and financial reporting. Firstly, increase scale complexity are enormous. Secondly, resulting exceeds what can be managed manually with rigour required by software, but building appropriate rigorous representations on necessary is, itself, a hard problem. Thirdly, ‘clinical pragmatics’ – practical data entry, presentation retrieval tasks must taken into account, so that intrinsic differences between needs users addressed. implies validation include use as implemented software.