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SY DE 542Design Phase 3: Multi-Variate Constraints

Configural & Mass Data Displays

Feb 7, 2005

R. ChowEmail: chow@mie.utoronto.ca

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Multivariate Constraints

• Relationships between 2 or more variables• May be at same abstraction level• May be across levels• Often equations

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Identifying Multivariate Constraints

• Re-visit Variable List• For each AH level, look:

– within a level– across levels

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Example: Conservation

• In – Out = Stored• Holds for Mass, Energy, Money,

Information• Also: People, Aircraft, Requests …• As long as nothing is transformed!

• Which AH level?• Think laws and principles …

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Example: Transformation

• If transformation occurs, identify defining relationship …

• Example: Food manufacturing• ? Butter + ? Sugar + ? Flour = ? Cookies

• Which AH level?• Relationships may be identified empirically

(based on experiments or history)

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Constraints Across Levels

• Shows how low level elements work towards high level purposes

• Examples from DURESS:– (1) Mass from 2 feedwater streams– (2) Energy leaving reservoir– (3) Flow split

(Vicente, 1999)

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Example (1): Mass from 2 Feedwater Streams

• MI1(t) = FA1(t) + FB1(t)• MI1(t): Which AH level?• FA1(t), FB1(t): Which AH level?• MI1(t) = FI1(t) ??

• Why should we be interested in MI1(t)?

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Example (2):Energy Leaving Reservoir

• EO1(t) = MO1(t) cp T1(t)• EO1(t): Which AH level?• MO1(t)?

• Cp:?• T1(t)?

• Why should we be interested in EO1(t)?

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Example (3):Flow Split

• FA1(t) = FVA(t) * VA1(t) VA1(t) + VA2(t)

• FA1(t), FVA(t): Which AH level?• VA1(t), VA2(t): ?

• Why would FA1(t) not be equal to VA1(t)?

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Designing for Multivariate Constraints

• Visually show relationships between variables

• Eliminate / reduce need for real-time computation by user

• Eliminate / reduce need for real-time lookup (of data tables, other documentation)

• Show context for relationships

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Configural Displays

• Idea is display of information for larger systems

• Individual pieces of data interact in a more global relationship - “higher order relationship”

• Right mapping makes that relationship emerge

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Definitions

• Low level data: usually individual sensor data

• High level relation: a more global and general display of what the data means

• Emergent property or emergent feature: a pattern or shape that is created from the low level data, is recognizable and has meaning

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AH -> Design Phase 3

• Bottom of abstraction hierarchy tells you what lower level data should be displayed

• Higher levels of the hierarchy tell you why those data are important, what relation has meaning

• Emergent feature must mean something to the task

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Examples

Network health

Network parameters

Heat transfer efficiency

T1, T2, T3, T4, water flow

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Configural/Separable/Integral?

• Separable– show each variable as a single output– equivalent to single sensor single indicator

display (SSSI)– integration or higher level relations must be

derived

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Integral Displays

• Show high level information but not low level information

• Low level information must be derived.

Normal Not normal

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Configural Displays

• Arrange low level data into a meaningful form

• whole is greater than the sum of the parts• based on principles of gestalt psychology

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Separable vs Configural

• Separable generally makes it easier to extract low level information– harder to integrate

• Configural makes it harder to extract low level information– easier to integrate

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Bar Graphs

• Can be configural and separable• Each element can be separated• Pattern can be configural

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Configural Displays

• Configural displays typically form an object • Sometimes called object displays• The emergent property is the shape of the

object• Emergent property can be found from your

abstraction hierarchy

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Emergent Features

• Example• two variables, x, y• could map x*y• only meaningful if area, x*y has meaning

for the task• good mapping x=mass, y=velocity,

area=momentum

x

y

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Visual Mathematics

• Equality– Does x=y=z– horizontal line

• Addition– Does x+y=z

x y z

x

yz

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Visual Mathematics

• Simple average– Does z=(x+y)/2

• Multiplication– Does z=x*y

x yz

x

yz

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Visual Mathematics

• Division– does z=x/y

• Mapping– x - vertical– y - horizontal– z - tan(Ø)

• Ø = tan-1(z)

x

yØ

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N-gon Feature

Construction:

Select key variables that measure overall status.

Get normal values.

Normalize x/xnormal.

Determine alarm limits, colour coding.

Normalization creates the shape.

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Another Polar DisplayConstant angle

Variant radius

Not configural

Designed by Florence Nightingale

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Straight Line Feature

Individual temperatures Vessel temp profile, vessel state

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Design Exercise• You have been hired as an interface designer to work for Mrs.

Field’s cookies. Mrs. Field’s cookie plant is aging and the company has realised that they are losing production and potential profits whenever cookies turn out flawed. Sugar (S kg), butter (B kg) and flour (F kg) are mixed to make dough which is then dropped onto a conveyor belt. The conveyor belt runs through an oven at temperature T and the finished cookies exit the oven.

•  To make the best possible cookie, Mrs. Fields’ cookie research team has determined that the dough must consist of a consistent relation between the amounts of butter, sugar, and flour.. This is a general property of cookie dough which holds over all different kinds of cookies. Precisely,

•   Butter = ½ sugar, Sugar = 1/3 flour

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Mass Data Displays

• Basic Idea: to show large amounts of data in a way that is quickly understood

• to show global patterns in data without hiding data

• capitalize on human pattern recognition abilities and visual perception

• give an overview, a feeling for the behaviour of the process

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Comparison with Configural Displays

• Both are suited for overviews• both show global relations• both can make it hard to separate data,

get individual values

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Comparison with Configural Displays

• MDD typically handle larger amounts of data

• don’t form an object so much as a pattern• both show elemental data and don’t hide

data

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MDDs

• Are somewhat under-used in computer displays

• have been used for years in paper based displays

• similar to the idea of alarm lights in power plants

• “get a feeling” of system state• analogous to sounds, e.g. hums

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General Principles

• Show each piece of data as a simple mark on the screen (graphic atom)

• Establish the mapping of the dynamics– what changes?– how does the mark change?– graphic atom level changes such as size,

shape, colour

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General Principles

• Determine the arrangement of marks– what is the organization?– what is the mapping to location in the display

space?– Possibilities

• Topological - follow system connections• Type of Data - organize temps, pressures, etc.• Frame of Reference, scaling.

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General Principles

• What is the pattern that should emerge?• What does the display look like under

different conditions?• Separability: To what extent must the

operator be able to extract the individual value?

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ABB displays

Mass Data Display

Plant graphs

Plant mimic

Polar Star

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ABB MDD

Data are normal

Data are deviating

Mark is line

Change is in angle

Organisation is plant topology

Data are normalised so normal=horizontal

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ABB MDD

• Normalisation adds context• Not normal is more salient• Faults “cascade” through plant• Experimental results

– fault detection 20 times faster

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ABB MDD

• Other marks they considered• Circle• Lines change in thickness

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The Daisy Wheel

Website use (access and errors)

Mark is the line between elements

Clustering of lines shows information

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www.smartmoney.com/marketmapMass Data Display for Financial Market

Mark is rectangular shape, “Tile map”

Varies in Colour to show Gains and Losses

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Ozone levels in LA, 10 years

Technique: Coloured tiles

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Scatterplots

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Design Exercise

• It is estimated that Mrs. Field's produces 500,000 cookies a day.

• Each cookie is inspected for size, shape, and baking quality (undercooked, cooked, and overcooked). Design a mass data display for this situation. What sort of dimensions could you organize your display with?

•  (Note: you don't have to show all 500,000 cookies)

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Next Week

• Guest Lecturer: Prof. Greg Jamieson • EID for Petrochemical Processing• Work Domain + Task Analysis• Design and Evaluation• No slides will be posted

• Submit final checkpoint to Munira by email• Before Wed. Feb. 16, 5pm