SIntS 1314 T6 MentalModels

8/17/2019 SIntS 1314 T6 MentalModels

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Acknowledgements: Most of this course is based on the excellent course offered by Prof. Kellogg Booth at the

British Columbia Uniersity! "ancouer! Canada. Please acknowledge the original source when reusing these

slides for academic #ur#oses.

Mestrado em Informática Médica

SIntS 13/14 – T6Mental Models

Miguel Tavares Coimbra


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Summary

• Mental models vs. once!tual desi"n

• #uman "oal$oriented action

• Structural and functional models

SIntS 13/14 $ T6 – Mental Models


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%ecall& 'esi"n once!ts

• (ffordance

– visi)le constraints• Ma!!in"• *eed)ac+

– ausality ,true and false

+inds- – nderstanda)le action

• isi)ility• once!tual models

0ter factors&

– Transfer effects

– ultural associations

– Individual differences

desi"n conce!t is i"est level and o!en to inter!retation2

It is a starting point

sycolo"y of everyday tin"s5

'on 7orman 1899



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once!tual models& learnin" "oals

• eo!le ave mental models5 of o: tin"s :or+• ;e build our conce!tual models from many things inc&

– affordances – causality – constraints

– ma!!in" – !ositive transfer – !o!ulation stereoty!es/cultural standards – instructions – interactions ,inc. :/ oter !eo!le- – familiarity :it similar devices ,!ositive transfer-

• Models may be wrong es!. if attri)utes are misleadin"• Models allo: us to mentally simulate device o!eration• Te desi"ner as control over te system image



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(n o)


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(n o)ittle relation to analo" :atces

• ultural idiom& – Some:at standardiAed core controls and functions

• =ut still i"ly varia)le conce!tual model& – Must )e tau"t



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Mental models

BIn interactin" :it te environment :it otersand :it te artifacts of tecnolo"y #eo#le forminternal! mental models of themseles and ofthe things with which they are interacting.

Tese models !rovide #redictie andex#lanatory !o:er for understandin" teinteraction.

– 7orman ,in Centner D Stevens 1893-



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Mental models vs. once!tual

'esi"n

Mental models& something the user has (forms) – sers see5 te system trou" mental models – sers rely on mental models durin" usa"e – Tere are various forms of mental models – Mental models can su##ort users? interaction

once!tual desi"n& something the designer does – %efining te intended mental model

• #idin" te tecnolo"y of te system

– %esigning a suita)le system ima"e• (!!lyin" a!!ro!riate desi"n "uidelines

– Analysis usin" :al+trou"s5



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once!tual 'esi"n

• 'esi"nin" systems so users can understand tem

• (ssistin" te user to )uild useful mental models



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arious models

• %esign model is te desi"ner?s conce!tual model

• $ystem model is a model of te :ay te system :or+s

• $ystem image results from te !ysical structure of:at as )een )uilt ,includin" documentationinstructions la)els- – it is :at te user sees5

• User&s model is te mental model' develo!ed )y teuser trou" interaction :it te system – ser tries to matc te mental model to te system model



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7orman?s seven$sta"e model

a description of human goal-oriented action



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once!tual mismatc

• Misconce#tions a!!en :en user?s modeldiffers from te system model – 'ocument siAes measured in )ytes not !a"es or

:ords• Sun and SCI niE use different measures for files

– 'ates may )e in non$standard formats• ;ose )irtday is F8$F6$46 ,:at country are :e in-@

– serids ,and files- may )e constrained )y system

desi"n• userid mitcelGcs.u)c.ca

– Hrror messa"e may use system$s!ecific codes• Hrror 4F4 in #TT



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Some caracteristics of mental

models

• Incom!lete

• onstantly evolvin"

• 7ot accurate re!resentation – ,contain errors and uncertainty measures-

• rovide a sim!le re!resentation of a

com!leE !enomena• an )e re!resented )y a set of if$ten$

else rules



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(cuirin" mental models

• %uring system usage& – Te user?s o:n activity leads to a mental model – HE!lanatory teory develo!ed )y te user – 0ften used to !redict future )eavior of te system

• (bsering others usin" te system& – asual o)servation of oters :or+in" – (s+in" someone else to do tis for me5 – *ormal trainin" sessions

• )eading a)out a system – 'ocumentation el! screens for 'ummies5 )oo+s

Tis is done by the user ,not te desi"ner-



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%unna)le models&

J!ertur)? system to fi"ure out o: it :or+s

• Tese are dynamic models

– Includes a notion of causality

– doin" tis :ill result in tis5

• sed for ex#lanation – To understand :y te system res!onded as it did

– art of 7orman?s model of )eavior ,inter!retation-

• sed for #rediction – To select an a!!ro!riate action

– (lso !art of 7orman?s model ,intention-



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%unna)le models&

*doing x will result in y &+. ,stablish the goal to )e acieved

-. orm the intention for action to acieve"oal

/. $#ecify the action seuencecorres!ondin" to te intention

0. ,xecute te action seuence

1. Perceie te system state resultin" fromte action seuence

2. 3nter#ret te !erceived system state

4. ,aluate te system state :it res!ect tote "oal and te intentions

;at :ould )e a "ood

x@

'id y a!!en@;at does it mean@



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Mental model of a tele!one call

7e:man D>ammin"

*i" 13.K

0n oo+ 'ial Tone Silence

%in"in"=usy

0n oo+ (ns:ered 0n oo+

>ift off oo+ 'ial first di"it'ial remainder

;ait

lace on oo+lace on oo+

;ait for "reetin"



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ommon forms of mental models&

Many cate"oriAations. ery i"$level.

• $tructural: !resents an ima"e of what te system is – 'escri!tive ,not !rescri!tive- – ser may need additional +no:led"e to actually use it – 0ften more !o:erful / fleEi)le and often arder to use ,es!. if

don?t ave te necessary additional +no:led"e – Road map: it may show a particular ty!e of information, but it

isn’t customized to your particular use of that info.

• unctional: action$)ased2 descri)es how it is used – rescri!tive2 s!ecific2 often ste!$)y$ste! – 'oes not assume "lo)al or system +no:led"e

– Hasier to use )ut not very el!ful for !ro)lem$solvin" or dealin":it te uneE!ected

– Google directions: great when everything’s there; need morewhen there’s a roadblock.



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Structural models

resents an ima"e of what the system is• Most ma!s and scematics

– rovide a s!ecific vie: of te system2 use as needed5 – ifferent views: street, bus, bike maps of same region are

customized to drivers, bus riders and bikers. All are structuralmodels.

• 0)


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*unctional models

resents an ima"e of how the system is used

• Many +inds of user manuals – ste!$)y$ste! o:$tos5.

• State transition model – an"es in state need to )e visi)le52 ste! trou" tem.

– Telephone example, earlier slide; online shopping cart

• *unctional ma!!in"5 models – 'ifferent from a system ma!5L

– sers learn a seuence of actions to accom!lis tas+s – Te ma!!in"s need to )e rote$learned2 often ar)itrary

– and-held calculator maps !math" to key presses;

– "eyboard shortcuts



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#o: users use mental models

e.". State transition model

• 0ur vie: of usin" a tele!one is as a series ofstate changes – e.". re!resented as in tele!one eEam!le ,earlier-

• MM !redicts o: lon" :e :ait at various !oints – neE!ected delays or unfamiliar res!onses not

understood

• ;e try to fit :at :e ear into our model& – international calls may encounter different delays

– international calls may ave eEtra ste!s – international calls may result in different si"nals – a se!arate device eEerts control in faE calls



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To!ic& Mental models and user

interaction

• %eca! on !revious lecture on mental

models

• Mental models and user interaction



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;at mental models tell te user



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#o: do desi"ners identify a user?s

mental model@



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Te system ima"e

• 5e hae control over :at users see – %es!onsi)le for turnin" te system model $ system ima"e – oose a system ima"e to foster a "ood mental model

• Some interfaces literally dis#lay the system model

– (ll o)


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HEam!le

of :ere it el!s to ide system com!leEity

• ;ater faucet

– Te OrealP system model as inde!endent ot

D cold

– Te system image !rovides varia)le

tem!erature

– Some ta!s allo: se!arate tem!erature control

D volume control – =ot ot D cold5 and tem!erature D volume5

are Q '0*



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resentin" te system ima"e

• HE!licit re!resentation – rovide a current and consistent ma! of

everytin"

• Im!licit re!resentation – rovide cues a)out te system model

– ro"ressively eE!ose/reinforce te system model

– Tele!one voice mail eEam!le&

• Cood& #ou have three new messages. $ress % to hearyour first new message.

• =ad& $ress % to hear new message.



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once!tual models in desi"n

Cuideline R1

Proide a good conce#tual model

(llo:s user to !redict te effects of teir actions

• ro)lem&

– &esigner’s conceptual model is communicated via systemimage#

• (!!earance instructions system )eavior trou" interactiontransfer idioms and stereoty!es.

–If system ima"e does not ma+e model clear and consistent&• ser :ill develo! inconsistent conce!tual model.

• :ron"5 vs sim!lified5@



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once!tual models in desi"n

Cuideline RQ

• Make things isible – )elations between user&s intentions! re6uired

actions! and results are sensible andmeaningful.

– Hm!loy visi)le affordances ma!!in"s andconstraints.

– se visi)le cultural idioms.

– %emind !erson of :at can )e done and o: todo it.

• 7arro: your "ulfsL



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Cood ractices for once!tual

'esi"n• oose an intended mental model early in design• >in+ coice of mental model to style of interaction• 7ide system features tat conflict :it user?s activity• ,x#loit system image to foster intended mental

model• Hnsure tat system image is current and consistent• Ta+e into account users? existing mental models• (llo: for )ot noice and ex#ert mental models

• se sim#le! concrete! familiar meta#hors• 0)ey 8aw of 8east Astonishment5 ,0ccam?s %aAor-



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Mental models D !a!er !rototy!es&

%evealin" a mental model to te user

• ( story)oard or !a!er !rototy!e is one

:ay of illustratin" / documentin" an

intended or o)served mental model.

• seful for desi"n communication

analysis.

Interestin" for your u!comin" re!ort@



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Crocery (TM

,eEam!le of a !a!er !rototy!e-*irst te tas+&



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0ne :ay to !rototy!e te mental

model

#o: :ill you

!rototy!e

your !ro


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Summary

• 'esi"ner creates conce#tual models and

system models.

• ser models ,mental models- are

develo!ed )y te user.

• ommon mental model& ob9ectaction

model.



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%esources

1. ello"" S. =oot Introduction to #I

Metods niversity of =ritis olum)ia

anada

tt!&//:::.u"rad.cs.u)c.ca/cs344/current$term/

SIntS 13/14 T6 Mental Models
http://www.ugrad.cs.ubc.ca/~cs344/current-term/http://www.ugrad.cs.ubc.ca/~cs344/current-term/http://www.ugrad.cs.ubc.ca/~cs344/current-term/http://www.ugrad.cs.ubc.ca/~cs344/current-term/

SIntS 1314 T6 MentalModels

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