Talk:Object–role modeling

Link to Entity-Relationship modeling

the following text in the history section which relates OBR to ER:

conceptual approach is provided by Entity-Relationship modeling (ER).[4] Although ER models can be useful once the design process is finished, they are less suitable for formulating, transforming or evolving a design. ER diagrams are further removed from natural language, cannot be populated with fact instances, require complex design choices about attributes, lack the expressibility and simplicity of a role-based notation for constraints, hide information about the semantic domains which glue the model together, and lack adequate support for formal transformations.[3]

Now the section was removed twince by 118.67.22.34 with other explaination:

• Text about ER modelling here does is related to ORM
• Halpin's Work at Microsoft was self published at Microsoft, and constitutes 'original research'.

Now both arguments make no sense to me. Terry Halpin is a notable scientist, who is suppost to create original research. It doesn't really matter much where he published his work. So if there is something wrong with the text please explain first. -- Marcel Douwe Dekker (talk) 11:07, 22 October 2008 (UTC)

I have remove the questionable text here for now (which I added myself) and will try to find an other scientist to explain the relationship. -- Marcel Douwe Dekker (talk) 02:14, 27 October 2008 (UTC)

Problems with term "Fact"

According to the Wikipedia article on "Fact", the term "Fact" is commonly used to refer to something that is actually the case. In other words, A fact is a proposition that is verifiably true.

Object-role modeling(ORM) uses the terms "Fact" and "Fact Type" to refer to the propositions that are used by a modeler to describe a Universe of Discourse.

For example, the proposition "Fred lives in London" is called a "Fact" that is an instance of the "Fact Type" : "Person lives in City". However, there is nothing in ORM that prevents the modeler from entering propositions such as: "The Unicorn with the name Fred lives in London."

In other words, "Facts" in ORM can refer to things that are actually the case or to things that are fictional.

It seems to me that the ability to model both fact and fiction is a useful property of ORM but I wonder if the ORM community should stop using the word "Fact" and use a different term instead.

Any suggestions or comments? — Preceding unsigned comment added by The ken evans (talk • contribs) 15:51, 13 September 2013 (UTC)