Model Comm Patterns

8/3/2019 Model Comm Patterns

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8-2-2011 Chintan Amrit 1

Model Communication Patterns


Chintan Amrit

Maria Iacob


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Scope of the Patterns


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Pattern Name Semiotic Clarity Perceptual

Discriminability

Semantic

Transparency

Problem: A problem

growing from the

Forces.

Lack of Correspondence between

Symbols and Referent

concepts.

Diagrams with symbols that are not

discriminable reduce the

accuracy of their interpretation. .

If the semantic meaning of the symbols

is different from their intuitive or

natural meaning, then novice

readers would not be able to

discern its meaning.

Context: The current

structure of the

system giving the

context of the

problem

Designing/Using

a modelling language

Designing/Using


Designing/Using


Forces: Forces that

require resolution

Model Symbol redundancy,

excess or overload can cause

increase in complexity.

Shapes and connecting lines that are

too similar cannot be easily

distinguished by humans.

It is very hard for novices to understand

symbols that are semantically

opaque and especially if they aresemantically perverse.

Solution: The solution

proposed for the

problem

To limit diagrammatic complexity

it is preferable to have a

symbol deficit when

mapping constructs to the

language symbols

Symbols should be differentiated

using visual variables to increase

discriminability eg. increasing

visual distance, shape, redundant

coding, perceptual pop out and

text.

Symbols should provide clues to their

meaning and need to be

"intuitive" or "natural"

Rationale: Thereasoning behind

the solution

For a notational system thereneeds to be a 1-1

correspondence between

symbols and referent

concepts

Research in psychophysics hasestablished discriminability

thresholds

Semantically transparentrepresentations reduce cognitive

load because they have built-in

mnemonics.

Consequences: of the

result when the

pattern is applied

Decrease in complexity Increased accuracy for diagram

interpretation

The diagramming notation will be more

novice friendly

Related Patterns Semantic Transperency Perceptual Discriminability


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Discriminability

Semantic

Transparency

Problem: A problem

growing from the

Forces.


Symbols and Referent concepts.


discriminable reduce the accuracy of

their interpretation. .



natural meaning, then novice readers

would not be able to discern its

meaning.


structure of the system

giving the context of

the problem

Designing/Using


Designing/Using


Designing/Using


Forces: Forces that

require resolution








symbols that are semantically opaque

and especially if they are semanticallyperverse.


proposed for the

problem


it is preferable to have a symbol

deficit when mapping constructs

to the language symbols



discriminability eg. increasing visual

distance, shape, redundant coding,

perceptual pop out and text.


meaning and need to be "intuitive" or

"natural"

Rationale: Thereasoning behind the

solution

For a notational system thereneeds to be a 1-1 correspondence

between symbols and referent

concepts

Research in psychophysics hasestablished discriminability thresholds

Semantically transparentrepresentations reduce cognitive load

because they have built-in mnemonics.


result when the pattern

is applied


interpretation


novice friendly



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Semiotic clarity: There should be a 1:1 correspondence between

semantic constructs and graphical symbols.


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Symbol redundancy (synographs) in UML: there are alternative graphical symbols for

interfaces on Class Diagrams (left) and package relationships on Package Diagrams(right).

Symbol Overload (homographs) in ArchiMate: the same graphical convention can be

used to represent different types of relationships: generalisation (left) and

composition (right)


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Symbol Excess in UML: the comment is a useful notational feature but should not

be shown using a graphical symbol.


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Pattern Name SemioticClarity Perceptual

Discriminability

Semantic

Transparency

Problem: A problem

growing from the

Forces.










meaning.




the problem

Designing/Using


Designing/Using


Designing/Using


Forces: Forces that

require resolution











proposed for the

problem












"natural"

Rationale: The

reasoning behind the

solution

For a notational system there

needs to be a 1-1 correspondence


concepts

Research in psychophysics has

established discriminability thresholds

Semantically transparent

representations reduce cognitive load




is applied


interpretation


novice friendly



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Graphic excellence versus graphic mediocrity: (a) De Marco DFDs use clearly

distinguishable shapes for all constructs, while (b) Gane and Sarson DFDs use

rectangle variants.

Redundant coding: Using multiple visual variables (shape + color) to

distinguish between symbols.

a)

b)


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Discriminability

Semantic

Transparency

Problem: A problem

growing from the

Forces.










meaning.Context: The current



the problem

Designing/Using


Designing/Using


Designing/Using


Forces: Forces that

require resolution











proposed for the

problem












"natural"

Rationale: Thereasoning behind the

solution

For a notational system thereneeds to be a 1-1 correspondence


concepts

Research in psychophysics hasestablished discriminability thresholds

Semantically transparentrepresentations reduce cognitive load




is applied


interpretation


novice friendly



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Semantically Immediate

Semantically Opaque

Semantically Perverse

Fig. Spatial enclosure and overlap (right) convey the concept of overlapping

subtypes in a more semantically transparent way than arrows (left).

Both representations convey the same semantics: that a customer can be a

person, an organization, or both.


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Fig.Rich pictures: a rare but highly effective example of the use of

iconic representations in SE.


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Pattern Name Complexity

Management

Cognitive

Integration

Visual

Expressiveness

Problem: A

problem growing

from the Forces.

Excessive diagrammatic

complexity is one of the major

barriers to end user understanding

of diagrams.

Multi-Diagram representations that lack

conceptual and perceptual integration

are difficult to understand. .

Using a small range of visual variables

reduces the number of communication

channels through which a diagram can

be understood.

Forces: Forces

that require

resolution

Complexity has a major effect on

cognitive effectiveness as the

amount of information that can be

effectively conveyed by a single

diagram is limited by human

perceptual and cognitive abilities..

For multi-diagram representations to be

cognitively effective, they must include

explicit mechanisms to support

Conceptual and Perceptual Integration.

The use of few (one) visual variable to

encode

information results in the possibility of

sometimes only representing nominal

data and is cognitively inefficient

Solution: The

solution proposed

for the problem

Modularisation and hierarchy can

significantly reduce the

complexity of diagrams.

Diagramming notations that utilize

multi-diagrams must provide

mechanisms to assemble informationfrom different diagrams (Concep. Int.)

and simplify navigation and transitions

between diagrams (Percep. int.).

The visual notation should try to match

properties of visual variables to the

properties of the information to berepresented; the power and capacity of

the visual variable should be greater

than or equal to the measurement level

of the information "

Rationale: The

reasoning behind

the solution

Cognitive load theory shows that

reducing the amount of

information presented at a time to

within the limitations of working

memory improves speed and

accuracy of understanding and

facilitates deep understanding of

information content

The theory ofcognitive integration of

diagrams states that for multi-diagram

representations to be cognitively

effective, they must include explicit

mechanisms to support congitive and

perceptual integration.

Using a range of visual variables results

in a perceptually enriched

representation that exploits multiple

visual communication channels and

maximises computational

offloading.

Consequences: of

the result when the

pattern is applied

Novices and other

end users will be able to more

easily comprehend the diagrams.

The readers will be able to more easily

mentally integrate

information from different diagrams and

keep track of where they are.

The readers understanding of the

diagrams improves as multiple visual

channels are exploited.

Related Patterns Cognitive Integration ComplexityManagement

Perceptual Discriminability


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Fig. In the absence of complexity management mechanisms, ER

models must be shown as single monolithic diagrams.


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Fig. Hierarchical organization allows a system to be represented at

multiple levels of abstraction, with complexity manageable at each level.


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Management

Cognitive

Integration

Visual

Expressiveness

Problem: A

problem growing

from the Forces.



barriers to end user understanding

of diagrams.

Multi-Diagram representations that lack

conceptual and perceptual integration

are difficult to understand. .



channels through which a diagram can

be understood.

Forces: Forces

that require

resolution

Complexity has a major effect on

cognitive effectiveness as the

amount of information that can be

effectively conveyed by a single

diagram is limited by human

perceptual and cognitive abilities..

For multi-diagram representations to be

cognitively effective, they must include

explicit mechanisms to support

Conceptual and Perceptual Integration.

The use of few (one) visual variable to

encode

information results in the possibility of

sometimes only representing nominal

data and is cognitively inefficient

Solution: The

solution proposed

for the problem


significantly reduce the

complexity of diagrams.



mechanisms to assemble information

from different diagrams (Concep. Int.)

and simplify navigation and transitions




properties of the information to be

represented; the power and capacity of

the visual variable should be greater

than or equal to the measurement level

of the information "

Rationale: The

reasoning behind

the solution


reducing the amount of

information presented at a time to

within the limitations of workingmemory improves speed and

accuracy of understanding and

facilitates deep understanding of

information content

The theory ofcognitive integration of

diagrams states that for multi-diagram

representations to be cognitively

effective, they must include explicitmechanisms to support congitive and

perceptual integration.


in a perceptually enriched

representation that exploits multiple

visual communication channels andmaximises computational

offloading.

Consequences: of

the result when the

pattern is applied

Novices and other

end users will be able to more

easily comprehend the diagrams.

The readers will be able to more easily

mentally integrate

information from different diagrams and

keep track of where they are.




Related Patterns Cognitive Integration Complexity

Management



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Fig. Cognitive integration: When multiple diagrams are used to represent a

domain, explicit mechanisms are needed to support perceptual and conceptual

integration.


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Conceptual integration: Mechanisms to help the reader assemble

information from separate diagrams into a coherent mentalrepresentation of the system.

Perceptual integration: Perceptual cues to simplify navigation andtransitions between diagrams.

Fig. Contextualization: Each diagram should include its surrounding

context to show how it fits into the system as a whole.


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Management

Cognitive

Integration

Visual

Expressiveness

Problem: A

problem growing

from the Forces.



barriers to end user understanding of

diagrams.

Multi-Diagram representations that

lack conceptual and perceptual

integration are difficult to

understand. .



channels through which a diagram can be

understood.

Forces: Forcesthat require

resolution

Complexity has a major effect oncognitive effectiveness as the amount

of information that can be effectively

conveyed by a single diagram is

limited by human perceptual and

cognitive abilities..

For multi-diagram representationsto be cognitively effective, they

must include explicit mechanisms

to support

Conceptual and Perceptual

Integration.

The use of few (one) visual variable toencode information results in the

possibility of sometimes only

representing nominal data and is

cognitively inefficient

Solution: The

solution proposed

for the problem


significantly reduce the complexity of

diagrams.



mechanisms to assembleinformation from different

diagrams (Concep. Int.) and

simplify navigation and transitions




properties of the information to berepresented; the power and capacity of

the visual variable should be greater than

or equal to the measurement level of the

information "

Rationale: The

reasoning behind

the solution


reducing the amount of information

presented at a time to within the

limitations of working memory

improves speed and accuracy ofunderstanding and facilitates deep

understanding of information content

The theory ofcognitive

integration of diagrams states that

for multi-diagram representations

to be cognitively effective, they

must include explicit mechanismsto support congitive and perceptual

integration.


in a perceptually enriched representation

that exploits multiple visual

communication channels and maximises

computationaloffloading.

Consequences: of

the result when the

pattern is applied

Novices and other

end users will be able to more easily

comprehend the diagrams.

The readers will be able to more

easily mentally integrate

information from different

diagrams and keep track of where

they are.




Related Patterns Cognitive Integration ComplexityManagement



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Visual Variables [8]: these define a set of elementary graphical techniques for

constructing visual notations


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Figure.Visual Saturation: this cartographic legend uses 6 visualvariables to define 38 distinct graphical conventions.


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Different Visual Variables Have Different Capabilities for EncodingInformation: Power = Highest Level of Measurement That Can Be Encoded;

Capacity = Number of Perceptible Steps


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Pattern Name DualCoding Graphic Economy Cognitive Fit

Problem: A problem

growing from the

Forces.

When symbols are used without any

text to communicate models, it might

be difficult for the entire population to

understand. Especially those, who

differ in their spatial and visualabilities.

A large number of symbols, that

are not mnemonic, reduce

cognitive effectiveness.

Using one visual representation for

various tasks and/or audiences

(expert as well as novices), can limit

the understanding of the notation.

Forces: Forces that

require resolution

Providing textual cues to the meaning

of symbols aids interpretation,

especially when the symbols are not

semantically transparent, and improves

retention through interlinked visual

and verbal encoding in memory.

Empirical studies show that

graphic complexity significantly

reduces understanding of SE

diagrams by novices

Problem solving performance

(which orresponds roughly to

cognitive effectiveness) is

determined by a three-way fit

between the problem representation,

task characteristics and problem

solver skills

Solution: The

solution proposed for

the problem

The visual notation should represent

the information both verbally and

visually, representations of that

information are encoded in separate

systems in working memory and

referential connections between the

two are strengthened.

Simplifying the semantics

of a notation provides an obvious

way of reducing graphic

complexity.

Cognitive fit in a notation allows the

best of both worlds: a simplified

visual dialect for sketching and an

enriched notation for final diagrams.

Rationale: The

reasoning behind thesolution

Dual coding theory suggests that

using text and graphics together toconvey information is more effective

than using either on their own.

The human ability to discriminate

between perceptually distinctalternatives (span of absolute

judgement) is around 6 categories

per visual variable.

Cognitive fit theory states that

different representations ofinformation are suitable for different

tasks and different

audiences.

Consequences: of

the result when the

pattern is applied

The reader grasps the meaning of the

symbols quicker.

Novice readers will be less

affected by graphical complexity.

The notation will be understandable

by novices and experts, who will be

able to use both pen/paper as well as

modern graphics software.

Related Patterns Perceptual Discrimibility,Visual Expressiveness

ComplexityManagement



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Problem: A problem

growing from the

Forces.













Forces: Forces that

require resolution










diagrams by novices







solver skills

Solution: The


the problem











complexity.





Rationale: The











tasks and different

audiences.

Consequences: of

the result when the

pattern is applied


symbols quicker.







Related Patterns Perceptual Discrimibility,Visual Expressiveness ComplexityManagement Perceptual Discriminability


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Fig. Dual coding: the best of both worlds?


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Problem: A problem

growing from the

Forces.













Forces: Forces that

require resolution










diagrams by novices







solver skills

Solution: The


the problem











complexity.





Rationale: The











tasks and different

audiences.

Consequences: of

the result when the

pattern is applied


symbols quicker.







Related Patterns Perceptual Discrimibility,Visual Expressiveness ComplexityManagement Perceptual Discriminability


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A balancing act: To keep graphic (and diagram) complexity manageable, notationdesigners need to make decisions about what information to encode graphically,

what to encode textually, and what to include in supporting definitions.


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Problem: A problem

growing from the

Forces.

When symbols are used without any text

to communicate models, it might be

difficult for the entire population to

understand. Especially those, who differ

in their spatial and visualabilities.

A large number of symbols, that are

not mnemonic, reduce cognitive

effectiveness.


various tasks and/or audiences (expert

as well as novices), can limit the

understanding of the notation.

Forces: Forces that

require resolution

Providing textual cues to the meaning of

symbols aids interpretation, especially

when the symbols are not semantically

transparent, and improves retention

through interlinked visual and verbal

encoding in memory.

Empirical studies show that graphic

complexity significantly reduces

understanding of SE diagrams by

novices

Problem solving performance (which

corresponds roughly to cognitive

effectiveness) is determined by a

three-way fit between the problem

representation, task characteristics

and problem solver skills

Solution: Thesolution proposed for

the problem

The visual notation should represent theinformation both verbally and visually,

representations of that information are

encoded in separate systems in working

memory and referential connections

between the


Simplifying the semanticsof a notation provides an obvious


complexity.

Cognitive fit in a notation allows thebest of both worlds: a simplified



Rationale: The


Dual coding theory suggests that using

text and graphics together to conveyinformation is more effective than using

either on their own.







tasks and different

audiences.


result when the

pattern is applied


symbols quicker.

Novice readers will be less affected

by graphical complexity.





Related Patterns Perceptual Discrimibility,Visual Expressiveness

ComplexityManagement



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Fig. Cognitive fit is the result of a three-way interaction between the

representation, task, and problem solver.


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Fig. Notational requirements for hand sketching are different from

those for drawing tools and tend to limit visual expressiveness.


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Fig. Interactions between principles: + indicates a positive effect,- indicates a

negative effect, and indicates a positive or negative effect depending on the

situation.


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Pattern

Applicable for

the c-Map

Conceptual Model

Reason

Semiotic Clarity Yes

The c-Map tool provides a basic oval

shape, with possibilities of colouring it

and 2 possible line shapes. Hence there

is a major lack of correspondence

between symbols and referent concepts

Perceptual

Discriminability

Yes

The only two distinguishing factors

between the different concepts are the

size and the colour of the oval. Hence it

is not possible to distinguish the

concepts

Semantic

TransparencyYes

As only one oval is used it is not

clear what the symbol stands for

Complexity

ManagementNo

As the diagrammatic complexity is

not because of symbol overload

Cognitive Integration No There is only one diagram

Visual

ExpressivenessYes

There is indeed only one symbolwhich reduces cognitive effectiveness

Dual Coding YesThere is no text present to help in

the understanding

Graphic Economy NoAs the number of symbols is not

large

Cognitive Fit YesAs there are no two possible sets of

notation for experts and novices


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Pattern Name Metric Description at the

Language Level

Metric Description at the

Sentence Level

Semiotic Clarity Number of instances of symbol

redundancy, symbol overload andsymbol excess in the language

Number of instances of symbol

redundancy, symbol overload andsymbol excess in a diagram

Perceptual

Discriminability

Visual Distance: This is

measured by the number of visual

variables on which they differ and the

size of these differences (measured

by the number of perceptible steps).

Visual Distance in a diagram

Semantic

Transparency

Number of symbols that are

semantically opaque and perverse

Number of symbols that are

semantically opaque and perverse ina diagram

Complexity

Management

+1 if it doesnt allow either

modularisation or hierarchy

Diagrammatic complexity = No.

of instances/tokens in a diagram

Cognitive

Integration

+1 if it doesnt allow either

conceptual or perceptual integration

Number of Instances of lack of

conceptual and perceptual

integration

Visual

Expressiveness

8 - # information carrying

variables

Instances of: 8 - # information

carrying variablesDual Coding +1 if there is no dual coding for

variables

+1 for Instances of lack of dual

coding

Graphic

Economy

+1 if the # of semantic concepts

are high

+1 is there is no symbol deficit

+1 if there is no attempt to

increase visual expressiveness

Number of different symbols

Cognitive Fit Dependent Variable Dependent Variable


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Optimal Sentence level Model Quality (MQ) as:

Where,

(nr+ no + ne) represents the Semantic Quality,

where nr, no, ne represent symbol redundancy, overload and excess

respectively

vdrepresents the visual distancensemOpq represents the number of symbols that are semantically opaque

or perverse

cmngrepresents the complexity of the diagram

cint represents number of instances of conceptual and perceptual

integration

vexp represents 8 - number of information carrying variablesdcodrepresents the number of instances of lack of dual coding

geco represents the number of different symbols

Documents

Model Comm Patterns