Why is a document an Act

From HL7Wiki
Jump to navigation Jump to search


Why is document an Act?

Two short answers:

  1. We made a design decision in V3 early on that we would not model the real world directly but model what we observe or do that is of interest in the real world. Therefore we collect data about our observations, our prescribing etc etc i.e. we collect information about our activities or activities. Sometimes in healthcare, we collect the data about one or more acts and package that collection up into a document. Thus a document is simply a collection of acts and as such is an act in its own right.
  2. In the RIM, we have "red" classes, "yellow" classes "green", pink classes, cyan classes and cream classes. With the appropriate combinations of these classes you can say anything you like. Look at the definitions (not the names) and the attributes and choose the classes that fit the data you need to convey. The creation, use, and management of documents have, in principle, the same kinds of semantics as “red classes” (called “Acts” in the RIM) in terms of attributes, relationships to entities et al.
Note that this page does not cover the “are findings/conditions/concerns Acts” nor the “completeness of the RIM” discussion that some have raised as part of the discussion. Rene spronk 17:37, 6 Aug 2006 (CDT)

Electronic vs Physical

There is no essential difference between electronic and physical. A book on a floppy disk or memory stick is no different than a paperback.

“I'm the author of this book" and "My son ripped pages from this book" has a completely different meaning of the word "book" even though both are nouns.

The RIM forces you to make a choice when you want to talk about either a physical thing or an electronic thing, and it's the same choice. You can talk about the physical medium of the book - dimensions, number of megabytes, font style, byte encoding, etc. Alternatively, you can talk about the information that the book contains. You use different classes depending which aspect you want to deal with.

One of the differences is that if I take the paper prescription and put it in the photo-copier and press copy 9 times, I will end up with 10 different entities. Each can have a different status, I can shred one, turn another into a paper airplane, us another to line the bottom of my bird cage, etc. However, there is only one Act. That's because only one order has been issued. Photocopying the piece of paper didn't change that fact in any way shape or form (however much patient Smith might like to pretend that it has when they take the photocopies to different pharmacies :>).

So please lets stop arguing about electronic vs. physical vs. forgeries vs. copies. That's not what this is about. This is about the physical medium vs. the conceptual content. HL7 lets you talk about either or both. We use different classes depending which aspect you're talking about.

The biggest mistake people make is to discount Act as an information structure and think you have to be an Entity to be "persistent". Act and Entity are categories distinguished by the real-world substrate of the information. It works pretty straight-forwardly.

In short, a "paper document" can be tracked as an entity in the RIM (as a ManufacturedMaterial Entity), however, all information structures are abstract human thoughts (i.e. Acts) not atoms or molecules. There was a lengthy discussion in M&M on this very topic back in the 1990's.

Long version of the first (short) answer

A slightly more formal way of answering the question: We can consider that documentation is a series of statements and statements are the actions of recording something.

The word "act" has many meanings: some are documents of decisions or actions (an act of parliament), some are some are verbs (to act). However, this is strictly irrelevant and attempts to argue that because HL7 called a class an "Act" it must for ever have the properties of a particular use of that word are pointless and circular.

The "Act" class in the HL7 RIM by its very nature (as a class in a static information model) is concerned with information. It represents information (whether knowledge or perception) about something that has happened or may happen in the future. As with any name or word you can worry about its formal definition - which is of course made up of words - or you can look to how it is used.

If we are referring to the physical thing on which a document is written then it is a physical entity. However, if we are expressing the information in a document then it consists of statements of things that happened, might happen, should happen or are believed to have happened. These statements involve unsurprisingly the things that participate as subjects or objects of those actions. Inevitably therefore the information model representation of the information in a document is not expresses simply as an entity or indeed as an Act but as a combination of all the classes in the information model (which in the case of HL7v3 means a documentation is represented by a combination of classes from the RIM).


Some think that was unfortunate in the RIM to use the term "document" instead of "documentation." Normally, the RIM naming convention was intended to use the nominal form of a verb, e.g. documentation for the infinitive "to document;" observation for the infinitive "to observe." However, that pattern was not always followed. Also, people do get sloppy in the narrative in the language used to describe the RIM. Almost all Acts can be read as activities that are 'performed': the Observation was performed, the Procedure was performed, the Supply was performed. But 'the Document was performed' doesn't make sense. What is intended though, is the act of Documentation. I'm not sure if it's proper English, but 'the Documentation was performed' sounds a lot better. It is this simple change that switches the perspective from entity-like to activity-like.

Note that one important reason why "documentation" was not chosen as the name of this class is because all Act event records in the RIM are documentations of real world activities. The Document act is for those conventional documents in the sense of having title, headed, sections, and free text. Naming this class "Documentation" would reinforce the very common misconception that only documents, not other Acts, can establish proper documentation, and that is of course not true. A better name that is still a nominalized verb might be "DocumentEdition" to make clear that it is the act of editing (and then releasing) a document. --Gschadow 19:40, 15 Aug 2006 (CDT)

Note [also] that no published healthcare information model models the "real world" directly, certainly not those models which would take a "document oriented" or a "health record structure oriented" perspective. These are in fact twice removed from the real world. Conversely, the RIM models the real world quite directly because real physical things and real people activity are both directly represented in the RIM. But, as this page explains, the essence of a document is not a physical thing. --Gschadow 19:32, 15 Aug 2006 (CDT)

(To see the discussion thread about this on the HL7 Listserv: "Why is document an act?" )