Conceptual Modelling vs Information Modelling Rolf Wohed Ph
- Slides: 14
Concept(ual) Modelling vs Information Modelling Rolf Wohed, Ph. D Sweden SIS/Hifab 1
Modelling today • Widely used for business and information analysis, technical design et c. • Long experience (over 20 years) of using distinct modelling levels • Used in development of national standards (both in GI and elsewhere) – Facilities, Road and rail networks, Surface water systems …, healthcare, telecom, … 2
Use of Concept Modelling • Analysis and acquisition technique • Definition of a common language • Basis for precise formulation of goals, rules, policies, processes and so on • Basis for definition of spatial (math. ) concepts • Basis for design of application schemas • Explanation of application schemas when applying standards • Basis for dictionaries in application areas 3
Why ”meaning”? Term ISO definition Concept unit of thought Conceptual Model model that defines the concepts of a universe of discourse 4
Semantic vs. information perspective Semantic perspective Information perspective Lake + located at [1. . 1]: Location + described by [1. . 1]: Surface Lake + name [0. . *]: String + depicted by [1. . 1]: GM_Surface Distinguishing characteristics Information requirements 5
Ogden’s triangle Concept A Unit of Thought gives rise to is used to communicate about A cat ”Cat” is intended to refer to Real World Occurrence Term A symbol
Context provides meaning Ideas Different Units of Thought Differing interpretations is used to communicate about gives rise to A cat ”Cat” A Symbol is intended to refer to Real World Occurrence Term 7
Eugen Wüster: ” A Term is semantically defined by its underlying concept. A Concept is defined by its relationships with other concepts. Relationships are also concepts. ” 8
Concept Modelling • • Define the purpose of the model Distinguishing characteristics Define in terms of other concepts “Bootstrap” at peripheral concepts 9
Simple example Concept Interpretation (including features) Water table + soil type + depth Water table + building + dimensions Water table + avg distance from road + width Red groundwater level narrow shelf, ledge on a building ditch <Use dictionary> 10
“Realistic” example Concept located at 1. . 1 Lake content type 1. . 1 Inland location Fresh water: Location 1. . 1 described by {surface area > 1000 m 2}1. . 1 has measured {max(depth) > 1 m} 1. . * has Surface Depth + measure + date 0. . * By lake we mean something that has an inland location, contains fresh water, is described by a surface area of at least 1000 m 2 and has a maximum measured depth of at least 1 m. 11
Realistic example cont. Information Concept model «Type» GM_Surface defined in Lake + Name + Max. Depth instance of depicted by 1. . 1 Lake surface For a lake we want to handle name, maximum depth and its spatial approximation. 12
Dynamic properties Operation service that can be requested from an object to effect behaviour Feature Operation operation that every instance of a feature type may perform Dam +Raise() +Lower() Dam +level: Meter +Capacity: Cubic meter 13
Contact info Rolf Wohed (rolf. wohed@hifab. se) Torbjörn Cederholm (torbjorn. cederholm@sis. se) SIS, Swedish Standards Institute 118 80 Stockholm, Sweden 14
