3. Language Languages Languages are human communication instruments for the understanding of items (linguistic definition) Languages are the basis of any scientific discourse Languages are systems of signs (semiotic definition) Linguistic signs are arbitrary and conventional Arbitrarity:The choice and construction of signs is arbitrary, i.e. there is no direct connection between the sign and the singified item (i.e., e.g. a „customer“ is not necessarily represented as a picture of a customer) Conventionality:The semantics of the signs is result of a convention – a consensus of the speech community (e.g. scientists, modelers)
4. Classification of Languages Natural Languages systems of signs that have originated in an evolutionary way no complete definition of syntax and semantics natural languages evolve naturally (e.g. slang, dialects etc.) extremely expressive extremely redundant, potentially fuzzy and inconsistent Statements of natural languages can be interpreted in different ways Communication in natural language is not only dependent on the signs (gestures, intonation)
5. Natural Languages Universal Languages Are able to express „almost everything“ (Morris) Are not assigned to specific domains No dedicated application area Huge speech community Dynamic vocabular that is not defined clearly Examples: English, Russian, German, … Do not distinguish between language and meta language
6. Natural Languages Terminology Subset of universal language Is assigned to a particular domain Scientific disciplines Industry sector Business class Company … Application-driven, serving task fulfillment Are the basis of organizational action Comprise a finite set of terms and application rules e.g.: legal texts (juristic language), „officialese“
7. Terms as Sings of Natural Languages The Term „Term“ A termis a linguisticsignthatconsistsofthefollowingcomponents Word (name): sequenceoflettersas medium ofthesign Intension: „idea“ oftheterm, itssemanticsandcharacteristics Extension:setofobjectsthatarenamedbytheterm
8. Intension and Extension Examples Different name, different intension, different extension Different name, different intension, same extension Customer Product Debitor Customer
9. Intension and Extension Examples Different name, same intension, same extension Same name, different intension, different extension Invoice Bill Synonyms! Party Party Homonyms! (politicalincorporation) (celebrationevent)
10. Classification of Languages Formal Language A system of signs that is based on a calculus calculus: Methodology that is used to construct figures out of a set of basic signs (alphabet) following particular rules formal definition of syntax and semantics Semantics are classified as „defined formally“ if the definition of the sementics is based on mathematical rules (Sommerville 2001) Advantages Clarity Consistency Redundancy-free
11. Classification of Languages Semi-formal Languages Visual, diagram-based languages that contain textual elements (Remme 1997) Syntax is defined formally, definition of semantics is missing Signs of semi-formal languages consist of graphical elements and textual signifier (i.e. a node in a graph-based process modelling language „check invoice“) Semi-formal languages encounter some probolems that result from the application of natural languages Redundancy Fuzziness Inconsistency Resolution approaches: Standards, ontology
12. Formal andnaturallanguageaspectsof semi-formal languages Example: EPC Natural language aspects A document is relevant for a business transaction „Process“ is a task that transforms an object (the document) A document has to arrive prior to ist processing … Formal languages aspects Defined symbols Graph is directed Functions are followed by events Events do not follow events … Documenthasarrived Process document Document processed
13. Specification of Languages Possibilities to avoid problems of natural languages Technical term models Glossaries Term relationship models Ontologies Language standardisation Formal definition of the natural language‘s syntax and semantics Language application conventions Domain-specific languages (e.g. PICTURE)
18. Model Theroy Characteristics of Models (Stachowiak 1973): Mapping: a model is always related to an original that is being mapped The original consists either of a natural object or a mental construct Reduction:a model does not describe the orininal in total Non-relevant aspects are left out Important aspects are emphasized The model may contain additional aspects that do not exist in the original Pragmatics: a model has a particular purpose that is valid for a certain time and for a set of users
19. Model Theroy Relationship between model and original Original Model Mapping AdditonalAspects Reduction Cf. Stachowiak(1973)
20. Mapping mapping-orienteddefinitionofmodels (Kosiol 1968) Structuralandbehaviouralequivalenceof original and model Structuralequivalence (isomorphism) Structuralequivalenceisrestrictedtothe model apsectsthatare relevant forthe model purpose structuralsimilarity (homomorphism) Criticism Itisassumedthatthemodellerisabletorecognisethe original completely (i.e. in total andobjectively) But: everymodellerissubjective constructionorienteddefinitionofmodels
21. Construction Modelling is a process A person… constructs a representation of a (real or mental) issue… On the basis of her/his perception Modelling is purpose-driven The purpose is defined by the modeller Model components have to be considered relevant by the modeller Models are represented with artificial, (semi-)formal languages
22. Construction Consequences that arise from the construction-oriented model definition Models are not objectively true or false Models are more or less purposeful at most The choice of a particular model out of a set of possible models is exclusively dependent on decisions of a modeller In order to guarantee usefulness of a model: consensus of modellers and users
24. Definition of the Term Model in Information Systems A model is an abstract representation of a business issue (the original) for subjective purposes It is the result of the construction of a person that defines a representation of an original at a certain time for a certain group of recipients using a particular artificial language.
25. Definition of the Term Information Model An information model is an abstractrepresentationof a businessissue (the original) forthepurposeofapplicationsystemsand organisational design Itistheresultoftheconstructionof a personthatdefines a representationof an original at a certaintime forapplicationsystemsand organisational designersusing a modellinglanguage.
27. Modelling Technique Operationalised approach for model construction 2 Aspects: Modelling language: Elements to build a model Instructions for the use of the language Modelling Technique Basic Aspect DerivedAspect Instructions Modelling Language Basis for
28. Aspectsof Modelling Languages ConceptualAspectofthe Language Language elementsandtheirsyntacticalrelationships Abstract syntax In addition: semanticsoflanguageelementsandtheirrelationships (description in naturallanguage) Example: EPC: An EPC is a bipartite, directedgraphfortherepresentationofbusinessprocesses Modelling elementsarefunctionsandeventsthatareconnectedbycontrolflows Functionsrepresentbusinesstasksandare time-consuming Events representstates …
29. Aspectsof Modelling Languages Representational Aspect Representation of language elements and their relationships Particular syntax Example EPC: Functions are represented by rounded, green coloured rectangles Events are represented by flattened, red coloured hexagons Control flows are represented by directed edges. The direction is indicated by an arrow
30. Aspectsof Modelling Languages A modellinglanguagecansupport different representations A newrepresentationdoes notimply a newlanguage! Example EPC:Representationoflanguageelementsthroughicons Function: workingemployee Event: explosion Representationofthecontrolflowthrough „fancy“ Edges
31. Instructions … describe how to construct a model with a modelling language … are therefore derived from the modelling language Example EPC: The tasks that are performed in a business process have to be identified and subsumed as functions Triggering or resulting states have to be identified and subsumed as events The temporal and logic order of functions and events has to be represented as control flow The model elements and relationships have to be represented with symbols
32. Modelling Languagesand Modelling Techniques Modelling Technique Basic Aspect DerivedAspect Instructions Modelling Language Basis for 1:n 1:1 ConceptualAspect Representational Aspect
33. Modelling Method(ology) Defines the essential tasks of one or more model development phase(s) Modelling techniques as constitutional elements Modelling views (cf. ARIS) Development layers (cf. ARIS)
34. Modelling Method(ology) Method(ology) 1:n Modelling Technique Basic Aspect DerivedAspect Instructions Modelling Language Basis for 1:n 1:1 ConceptualAspect Representational Aspect
