Modelling Languages: (mostly) Concrete (Visual) Syntax Hans - - PowerPoint PPT Presentation

▶

Aug 19, 2022 169 likes •761 views

Modelling Languages: (mostly) Concrete (Visual) Syntax Hans Vangheluwe Antwerp 26 August 2014 2 3 4 5 6 Causal Block Diagrams (syntax) 7 Causal Block Diagrams (semantics) 8 Operational Semantics 9 Causal Block Diagrams (semantics)

SLIDE 1

Modelling Languages: (mostly) Concrete (Visual) Syntax

Hans Vangheluwe

Antwerp 26 August 2014

SLIDE 2

2

SLIDE 3

3

SLIDE 4

4

SLIDE 5

5

SLIDE 6

6

SLIDE 7

7 Causal Block Diagrams (syntax)

SLIDE 8

8 Causal Block Diagrams (semantics)

SLIDE 9

9 Operational Semantics

SLIDE 10

10 Causal Block Diagrams (semantics)

SLIDE 11

11 Formalism Transformation Graph (FTG)

SLIDE 12

12 Modelling Languages/Formalisms Syntax and Semantics

SLIDE 13

13

Explicit Modelling of Modelling Languages/Formalisms

Modelling Languages/Formalisms Syntax and Semantics

SLIDE 14

14 Semantics of Meta-models

What is the semantic domain of the Class Diagram formalism (when used as a meta-modelling language)?

SLIDE 15

15 Textual Languages

Modelling Languages/Formalisms

SLIDE 16

16 Textual Languages

Textual Languages

“this sentence is very short”

Individual letters in an alphabet
Combined into words
Combined in to sentences in a language
Letters in words specifjed by regular expressions
Words in a language specifjed by a grammar
Symbols are combined by “is to the right of”

SLIDE 17

17 Textual Languages

SLIDE 18

18 Visual Languages

SLIDE 19

SLIDE 20

20

Plex

Visual Languages

SLIDE 21

21

Graph

Visual Languages

SLIDE 22

22

Connection Types

Visual Languages

SLIDE 23

23

Iconic

Visual Languages

SLIDE 24

24

Box

Visual Languages

SLIDE 25

25

Visual Language Classes

Visual Languages

SLIDE 26

26

Hybrid Languages

Visual Languages

SLIDE 27

27

Syntax-directed Visual Editors: model behaviour

Visual Languages

SLIDE 28

28

Syntax-directed Visual Editors: model behaviour

Visual Languages

SLIDE 29

29

Syntax-directed Visual Editors: model behaviour

Visual Languages

SLIDE 30

30

Syntax-directed Visual Editors: freehand (early stages of multi-domain project)

Visual Languages

SLIDE 31

31

Different Media: Gestural Interaction, Sound, ...

Visual Languages

SLIDE 32

SLIDE 33

33

Introduction

Visual notations pre-date textual ones
Visual notations are important for

Modelling and Software Engineering

Humans are excellent pattern

recognizers

Need cognitively effjcient and effective

notations. Cognitive effectiveness = speed, ease and accuracy with which a representation can be processed by the human mind

``Physics'' of Notations

a DSVL @ Lascaux

SLIDE 34

34

Introduction/Rationale

Visual notations are often introduced without underlying theory or rationale

``Physics'' of Notations

Many visual notations for same concepts. No rigorous way to compare effectiveness and hence no clear design goal.

SLIDE 35

SLIDE 36

SLIDE 37

SLIDE 38

SLIDE 39

SLIDE 40

40

Communication Theory

``Physics'' of Notations

SLIDE 41

41

Encoding: 8 visual variables to (graphically) encode information

``Physics'' of Notations

SLIDE 42

42

Decoding

``Physics'' of Notations

automatic, fast, parallel slow, large effort, sequential Appropriate notations » offmoad some of the burden from cognitive to perceptual Note: “dual channel theory”: brain processes textual/audio in parallel with visual data

SLIDE 43

43

Principles for Designing Effjcient and Effective Visual Notations

``Physics'' of Notations

SLIDE 44

44

Semiotic Clarity (semiotics = study of signs and sign processes)

``Physics'' of Notations

1 to 1

SLIDE 45

45

Perceptual Discriminability

``Physics'' of Notations

SLIDE 46

46

Perceptual Discriminability

``Physics'' of Notations

should be easy to distinguish visual symbols ability to distinguish is determined by visual distance larger visual distance » faster, more accurate recognition

number of visual variables on which they differ and the size of the differences
shape is the main visual variable

13

SLIDE 47

47

Perceptual Discriminability

Software Enginering notations mostly use rectangle variants Use redundant visual encoding to increase distance (e.g., textual + visual)

``Physics'' of Notations

SLIDE 48

48

Semantic Transparency

The meaning of a symbol can be inferred from its appearance (intuitive) Symbols can be:

``Physics'' of Notations

Semantically Immediate
Semantically Opaque
Semantically Perverse

Software Engineering notations are usually abstract (non-intuitive) Domain-specifjc icons are intuitive

SLIDE 49

49

Semantic Transparency

``Physics'' of Notations

SLIDE 50

50

Complexity management (# elements in diagram » cognitive overload)

``Physics'' of Notations

SLIDE 51

51

Modularization/Hierarchy

``Physics'' of Notations

SLIDE 52

52

Cognitive Integration (different notations)

``Physics'' of Notations

Conceptual integration (coherent mental model)
Enable navigation and transition between notations

SLIDE 53

53

Visual Expressiveness

Number of visual variables used (UML, mostly shape, no colour) 8 degrees of visual freedom (0 = non-visual – 8 = visually saturated)

``Physics'' of Notations

SLIDE 54

54

Visual Expressiveness

Different visual variables have different capacity to encode information

``Physics'' of Notations

SLIDE 55

55

Dual Encoding

Combine Textual and Visual Supplement rather than duplicate (e.g., cardinality values) Reinforce meaning

``Physics'' of Notations

SLIDE 56

56

Graphic Economy

Not too many symbols. If many, provide legend
Limit on human discrimination capability (6 levels per variable)
Upper limit on graphic complexity

How?

``Physics'' of Notations

SLIDE 57

57

Cognitive Fit

Adapt choice of visual notation to

Task
Audience novices and experts

Adaptation may be dynamic (“learn” about Task/User profjciency) Representation medium

``Physics'' of Notations

SLIDE 58