RE: Abstraction in Science, Mathematics, Software, and Markup

["Costello, Roger L." <costello@mitre.org>]

Hi Folks,

Is there a difference between abstraction and reuse?

Suppose I observe that all appliances have a model number, a description, and a warranty. Subsequently I create this complexType:

    <xsd:complexType name="appliance">
        <xsd:sequence>
            <xsd:element name="model-number" type="xsd:ID"/>
            <xsd:element name="description" type="xsd:string"/>
            <xsd:element name="warranty" type="xsd:string"/>
        </xsd:sequence>
    </xsd:complexType>

Is that complexType an abstraction?

It is clearly a reusable thing. But I am not convinced that it is an abstraction because it is hardcoded to specific element names. What do you think?

Do you think that we (the XML community) have powerful mechanisms for creating abstractions? If not, what is missing? If yes, please provide an example of a powerful abstraction that you have created or you have seen created. What makes it powerful?

/Roger