{"id":340,"date":"2024-03-01T15:49:05","date_gmt":"2024-03-01T14:49:05","guid":{"rendered":"http:\/\/localhost\/?page_id=340"},"modified":"2024-09-17T08:44:07","modified_gmt":"2024-09-17T06:44:07","slug":"standards-comparison","status":"publish","type":"page","link":"https:\/\/transmodel-cen.eu\/index.php\/standards-comparison\/","title":{"rendered":"Standards comparison"},"content":{"rendered":"\t\t
\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t

Standards comparison<\/h1>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t

A detailed comparison between data models is defined as an\u00a0oriented<\/span>\u00a0correspondence mapping (m) between a ‘source’ model S and a ‘target model’ T.<\/p>

\"\"<\/p>

In the comparison method described in \u201cMethodology for comparing data standards” (link to paper to come)<\/em>\u00a0the ‘source’ model is the Contributing Standard (marked by a ‘S’) and the ‘target’ model, the Reference Model (marked by a ‘T’).<\/p>

A comparison of data standards is often lead in view of a conformance statement. Thus, the following steps are of importance:<\/p>

A. Determination of a Reference Standard<\/h2>

The comparison (mapping) of standards is preceded by an important step: the definition of the Reference Standard.<\/p>

A Reference Standard is a specification of which the scope covers a particular data domain in a most comprehensive way. Other standards are Contributing Standards.<\/p>

In other words: the scope of a Reference Standard is such that the standard is specifically designed to describe\/publish data for a particular data domain D, whereas the scope of a Contributing Standard is such that this standard only refers to (uses) the data of D to better describe other concepts.<\/p>

In many cases, Transmodel has to be considered as the Reference Standard Model.\u00a0\u00a0<\/span><\/p>

In some cases, the INSPIRE data model is recommended as the Reference Model (see https:\/\/publications.jrc.ec.europa.eu\/repository\/handle\/JRC118744<\/a>).<\/p>

B. Consideration of same levels of abstraction in the comparison<\/h2>

In comparing data standards (mapping of data standards), it is important to understand the level of abstraction being considered. Using higher-level modelling languages such as UML, etc, it is possible to model the intent of data models in an implementation independent manner, i.e., as a\u00a0conceptual<\/span>\u00a0model<\/span>.<\/p>

Any comparison of standards must of course be aware at what level of abstraction the standards operate: <\/span>compare like with like<\/b>.<\/p>

Where a concrete format does not have a formal conceptual model underpinning it, it can still be extremely useful to use a conceptual model (e.g., created by reverse engineering) to make the initial comparison, as it may give a clearer separation of concerns.<\/p>

\"\"Use of conceptual models for the comparison of different levels of abstraction<\/span><\/em><\/p>

Consider the conceptual model of the data standard to be compared with Transmodel.\u00a0<\/span><\/p>

C. Using a Mapping table<\/h2>

In order to be able to represent the correspondence in a simple way in the form of a Mapping Table, a Mapping Table template has been adopted. The header of the Mapping Table is as below.<\/p>

\n\n\n\n\t
#<\/td>Source Class<\/td>A (O=Own; R=Relationship)<\/td>Source Attribute Relationship<\/td>Source Attribute type
\nSimple type
\nComplex type
\nEnumeration <\/td>		Source multiplicity<\/td>Description (as in the Source)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/p>

Target elements = result of mapping<\/h2>

\n\n\n\n\t
Target correspondence indication; comments<\/td>Corresponding Target class\/attribute<\/td>Exact correspondence to target class 1:1<\/td>Exact correspondence to target attribute 1:1<\/td>Source-specific – new (class.) 1:0<\/td>Source additional attribute without contradiction 1:0<\/td>Belonging to a group of Source elements corresponding to a Target class N:1<\/td>Source element derived from several target attributes 1:N<\/td>Other<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/p>

Mapping Table template (link to paper to come)<\/span><\/em><\/p>

In brief, there are the following different levels of comparison:\u00a0<\/span><\/p>