Dear all, Following a discussion with Martin I am attaching the introduction to basic CRM concepts for the CRM document which is to be followed by the graphical representations and examples. We anticipate changes when all material is considered together.
------------------------------------------------------------ Introduction to basic concepts The following paragraphs explain core CRM concepts. The CRM can describe entities which remain relatively stable with the passing of time (E77 Persistent Item) and have identity based on the continuity or continued availability of their properties. These include, among others, monuments (e.g. E22 Human-Made Object) and mental ideas (e.g. E28 Conceptual Object). These entities are prone to change through human activity, biological, geological or environmental processes, but are regarded to exist as long as such changes do not alter their essence (their identity). For example, the Great Sphinx of Giza may have lost part of its nose, but there is no question that we are still referring to the same monument as that before the damage occured, since it continues to represent significant characteristics of an overall shaping in the past which is of archaeological relevance. The CRM also includes entities (E2 Temporal Entity) which are themselves time-limited processes or evolutions within the passing of time. They necessarily involve an affected material, social or mental environment, in the form of E77 Persistent Items or continuous substance, such as the atmosphere. They include among others making things by humans (E12 Production) and geological events (E5 Event). Once these entities occur, they can only be experienced through observation or recordings. Evidence of such entities (E2 Temporal Entity) may be preserved on material objects being permanently affected or recorded through oral history. Therefore a basic distinction of records modelled through the CRM is between instances of E77 Persistent Item (endurants) and instances of E2 Temporal Entity (perdurants). In most cases this distinction is adequate to describe database records. In exceptional cases, where we need to consider complex combinations of changes of spatial extent over time, the concept of spacetime (E92 Spacetime Volume) also needs to be considered. E92 Spacetime Volume describes the entities whose substance has or is an identifiable, confined geometrical extent that may vary over time, fuzzy boundaries notwithstanding. For example, the built settlement structure of the city of Athens is confined both from the point of view of time-span (from its founding until now) and from its changing geographical extent over the centuries, which may become more or less evident from current observation, documents and excavations. Even though E92 Spacetime Volume is an important theoretical part of the model, it can be ignored for most practical documentation and modeling tasks. We explain these concepts with the help of graphical representations in the next sections. ------------------------------------------------------------ All the best, Thanasis -- Dr. Athanasios Velios Reader in Documentation Ligatus University of the Arts London This email and any attachments are intended solely for the addressee and may contain confidential information. If you are not the intended recipient of this email and/or its attachments you must not take any action based upon them and you must not copy or show them to anyone. Please send the email back to us and immediately and permanently delete it and its attachments. Where this email is unrelated to the business of University of the Arts London or of any of its group companies the opinions expressed in it are the opinions of the sender and do not necessarily constitute those of University of the Arts London (or the relevant group company). Where the sender's signature indicates that the email is sent on behalf of UAL Short Courses Limited the following also applies: UAL Short Courses Limited is a company registered in England and Wales under company number 02361261. Registered Office: University of the Arts London, 272 High Holborn, London WC1V 7EY
