From: AAAI Technical Report WS-93-07. Compilation copyright © 1993, AAAI (www.aaai.org). All rights reserved.
An AI based frameworkfor collaborative design
N. E. Branki
Computer Studies Departmem
GlasgowCaledonian University
Cowcaddcns Road
Glasgow G4 0BA
Scotland
Abstract:
Designhas increasingly becomea collaborative endeavourcarded out by several individuals
with diverse kind of expertise .The individuals mayoccupyinstitutional roles in interaction
with each other. Designproblemsare multifaceted, solving themrequire the contribution of
several individuals, and the general approachhas beento breakdesign tasks into units which
representsindividualtasks and are intrinsically co-operative.
Researchin Artificial intelligence and especiallyintelligent agentsmayassist in collaborative
design. Agentscontain knowledge
about the players, tasks, and applications.
This paper commences
by discussing group workand its different aspects, researches
technologicalissues relevant to collaboration, and developsan AI based frameworkfor
collaborativedesign.
1. Background:
Acommon
practice in design is the splitting of a task into its components
parts, allowingthe
different participants to addressthemseparately. Forinstance, a part for an engineeris to
calculate the structure of the proposedlayout, whereasa facilities manager’spart is to devise
and measurethe spaceutilisation.
In co-operativesettings players do not only share informationbut also share applications.
Earlier workby (Clarke et al 1991) showedhowa co-operative dialogue between
individual and an application can be enabled. This wasachievedby construction user
interfaces whichincorporatedconsiderablelevel of knowledge
in relation to the individual and
the application. Theinterface is user conceptualisedemployingindividual’s knowledge,
individual’s tasks, the task domain,and the style of interaction requiredby the individuals. The
interface is extendedto support co-operativeworkfor design groups. It will incorporateco35
operativesupport handlers, that, for example,assist in choosingthe best application and the
best interaction technique.
2. Group Work
Groupworkinvolves a group of individuals workingon task to achieve a common
goal.
Individuals are members
of a design and client teamswith an overall objective to agree a
design. Groupshaveadvantagesover individuals performinga task. Collectively, individuals
are morelikely to include a broaderrange, and perhapsmoreappropriaterange, of skills and
knowledgepertaining to the task. Eachpersonbrings to the grouphis or her experience.
Groupworkinvolves muchof collaboration, co-operation, co-ordination, and communication
( Brankiet al 1992).
2.1 Collaboration
Collaboration occurs whentwo or moreplayers mayhave common,overlapping, or individual
goals. Theperiod of workingtogether mayinvolve the developmentof a design artefact (
hence co-operation) or mayinvolve discussions whichadvanceindividual goals¯
Collaboration does not require continuousco-operation, or continuouscommunication.
Periodsof individualworkmaystill be of benefit to the collaborativeefforts.
Otheraspects of collaborationinclude closer collaboration, that is the physicalproximity
whicha highly accurate predicator for collaboration; focus activity whichrefers to occasions
whenindividuals plan to workclosely on a shared task.
Collaborationalso demandsthat individuals share, exchangeand maintain informationfor four
reasons ( Olsen1989); tasks decomposition,gathering relevant expertise, poolingofdiff’erent
expertise and building shared goals¯ For a design based groupactivity, several tasks bear
deadlines and their allocation to groupmembers
to take themon is necessary; and also
because:
¯ different tasks requirea specialisedexpertise, different designspecialists are assembledto
handledifferent aspects of the problem.
¯ individual membershave limited perspectives or opinions on problems.Byconveninggroups
a larger set of ideas, wisdom,and judgementcan be pooled. Theyare morelikely to agree to
a decisionor a plan if they haveparticipatedin or just observedthe processthat led to it.
Newcomers
to a group workcan be exposedto learn a range of perspectives by observing
and/or participating in groupworkingon problems.
2.2 Co-operation
Co-operationis best describedas those periods of collaboration whereparticipants are
developingan artefact.
Co-operationbrings a synergythat can realise particular benefits. Fruitful interchangebetween
humanis based uponachieving such synergy. Thehypothesis is to makea computertruly cooperate whichmightbring similar benefits and one of the key requirementis that "ifa cooperativemachineis to be fully developedit mustsupportthe interactive updatingof the
shared knowledgebase ( Clarke et al 1993).
Co-operationis not a fixed pattern ofbehaviour,but it is changing,adaptiveprocess directed
to future results. Notall tasks will enableco-operativebehaviourto be realised. For instance,
tasks whichrequire a single correct answer(i.e. mathematicalproblems)tend to providelittle
scope for co-operation. However,a situation wheremorethan one alternative is sought
provide a problemsolving environmentwhichfavours co-operative behaviour. Empirical
evidenceto support this position has beenprovidedby two experiments.Firstly, it has been
confirmedthat the superiority of the groupover the individual will be highest for tasks which
afford a widerangeof possible solutions ( Thorndike1938). It has also beenfoundthat pairs
weresuperior to individuals whenworkingon problemsrequiring someoriginality or insight,
but not on moreroutine arithmetic problems( Husband1940).
Co-operation, with its agreed common
goals and behavioural norms, provide a secure
environmentfor makingimaginativeleaps. The potential advantagesof co-operative behaviour
within the designprocesshavebeenindicated by several researchers. In ’creative thinking’ face
to face groupmembers"spark off’ ideas against each other by an assembledeffect so that
finally the quality of ideas is higher than the individual couldhaveachieved(Broadbent1973).
2.3 Communication
A major feature of group workis the need to communicate.Communication
concerns the
transfer of informationbetweencollaborators. Referenceto an act of communication
is made
to an event involvingthe choice of an available medium
for the transfer of information.
Designis a communicative
activity in whichindividuals are called uponto decipher one
another’sworld. For instance, the early synthesisingof conceptsolutions maytake place in the
context of"decipherisation" within a design team ( Schon1983). Andwhenindividuals are
a communicativeand co-operative situation they maybecomeawareof the social needs and
effectiveutilisation of the resourcesat their disposal.
Communication
can also be twofold. Theinitial one focuseson, for instance, the client(s)
building uponthe contents of a brief, elaboratinguponthe description and the constraints for
the benefits of the designer(s). Theclient(s) is the majorsourceof information.In the final
one, the designer(s) will submitcompleteddesign for approvaland criticism. Thedesigner(s)
and the client(s) will considerthe designoptions and successivedesignswill be refined until
solution becomesacceptable.
2.4 Co-ordination
Co-ordinationrefers to the necessity in ordering the passageof informationamongst
collaborators, due to the reliance of one uponthe process performedby another.
Co-ordinationis also seen as a bodyof principals about howactivity can be co-ordinated,that
is, howgroup memberscan worktogether harmoniously. Co-ordination mayhave four
components
: goals (i.e. designproposals),activities (i.e. designing,ordering, construction),
actors (i.e. designand client teams), inter-dependenciesof action in order to achievegoals
Maloneet al 1990).
37
3. Technological Support to Collaborative Design: Research Issues
3.1 Computer-Supported
Co-operative
Work (CSCW)
CSCW
is an endeavourto understandthe nature and requirements of co-operative workwith
the objective of designingcomputer-based
technologiesfor co-operative worksettings (
Bannonet al 1989).
CSCW
is probably a novel idea in supporting co-operative workfor design groups. The
emphasisis to understandco-operativeworkas a distinct formof a work,and to support it
with the appropriate technology.
CSCW
research has taken two views for the developmentof shared applications to facilitate
co-operativework.Thefirst one is the" purposebuilt" applications such as generic tools for
sharing ( Crowleyet al, 1990). Thesecondview is the clean separation betweenapplication
and windowsystem functionality. This is possible with the facility offered by modem
window
systems. Window
systems have been extended by adding "pseudo-servers" betweenthe
existing workstationsoftware(servers) and the applications (clients) (Lawerset al,
In sum, CSCW
is a research field involvedin exploring a widerange of issues concerningcooperative workarrangementsand its support via informationtechnology.Studies in areas such
as Computer-AidedDesign, Computer-Integrated Manufacturing (CIM), Computer-Aided
SoftwareEngineering(CASE),etc.,are all relevant to the CSCW
field to the extend that they
study the use of computersto support co-operative workin different domains.
Within CSCW
technology, shared windowsystems allow the provision of multi-user interfaces
to existing applications withoutmodificationto the application. However,they are based on
the assumptionthat multi-user interfaces can be modelledas a collection of multiple single
interfaces. Sharedwindowsystemsdo not allow for different roles, experience, and
preferences amonggroup members.They are strictly WYSIWIS
(What-You-See-Is-What-ISee) the informationpresentedto one user is exactly the sameas to the other.
3.2 Multimedia in a Human-ComputerDialogue
In communicating
design intentions, or informationis conveyedin morethan one form.
Designersuse different types of mediawhichare essential in the reasoningprocess and are
related in common
use. Withintegrated office packages, a numberof designers see advantages
in being providedwith the ability to movebetweendifferent media.So for example,it is
advantageous
for a user to halt an animation,’cut’ a still frame,’paste’ in sometext, and
forward the wholeto someother user, whomight then choose to performsomegeometrical
operation such as changingthe perspective. Alternatively, the messagecan consist of an
animatedsequence,whichthe recipient mightchooseto replay selectively.
Multimediacan be viewedfrom two perspectives: the technological and the user-centred. The
former concentrates on whento use media and in what combinationto achieve the maximum
effect ( McCartney
1990). Thelatter focuseson the possibilities offered by the technology
the user.
Oneof the current areas of research in multimedia,is finding the appropriatenessof different
media,maintainingits consistency,and resolving mediaconflict, (Alty et al 1991)explores
someof these areas. Knowledge
based techniques have also been applied to multimediasuch
38
as workon relating different media,adaptiveinterfaces with the explicit representationand
use of the real-worldexpertise, dialogue-likeinteraction, personalisationand design for
usability (especiallyfor non-expert).
Anotheraspect of multimediais integration of different mediabecausetranslation between
themis not alwayspossible. A systemthat provides integration allows changein one mediato
be reflected in the other one. Onetype of output can serve both as input and output. For
instance changesin a residential mapby meansof a newhousingdevelopmentresults in a
revision to a graph, hencepredicting for examplepopulation growthand newtransport
demands.In another example,mapscould easily be extracted from imagesby means
illustrating roads, existing development,and projecting newones.
Multimediaintegration systemrequires a strategy for providingeasy and powerfulaccess to
informationof all types of media. It does not changethe differences betweenmediaby making
themaccessible to all users with equal ease. Suchsystemneeds an interface management
systemthat is consistent, flexible, and couldsmooththe transition betweendifferent media:the
"seamless"integration of media. Multimediaintegration systemwasproposedby ( Brankiet al
1992b)to use existing designapplications.
Aknowledgebase approachto mediaintegration wouldprobablyresult in an intelligent media
systemproviding sensible default options, by incorporating knowledgeabout the most
appropriatemediafor various situations.
Considerationsof multimediaare difficult with reference to links betweenmediaand
hypermediainevitably becomesa consideration. Oneof the mainadvantages of hypermedia
over multimediadatabases is that the technologyallows a user to browsea complexdatabase
withoutthe needto return to the indexlevel and formulatea retrieval query everytime a new
piece of informationis sought.
Currenthypermedialsystemsdo havea numberof limitations with the most significant being
that the links whicha user pursuesare typically specified in advanceby somescript writer.
Thereis desirable needfor a moredynamicinterface. This facility ultimately requires that the
systemcreates and/or destroyslinks at run-time, either in responseto someutility whichis
invokedby the user, or by performingknowledge-based
inferencing.
3.3 Intelligent Front-Ends(IFE)
In co-operativesettings individuals do not only share informationbut also share applications.
Animportantissue is the construction of user interfaces whichincorporates a considerable
level of knowledge
in relation to the user(s) and the application(s). Bydoingso, a
operative dialoguecan be enabled. Suchinterface is defined as one whichhelps users
overcometheir incompleteunderstandingof the computersystemand, in this support,
employsknowledge
of the user, the user’s tasks, the task domainand the style of interaction
required by the users (Sharrat 1991). For examplea shared drawingapplication wouldrequire
a WYSIWIS
modeof interaction, whereas a spreadsheet needs a command
of interaction
whichwouldenable users to viewthe samedata in different format. Theissue here is to
considerthe types of sharedinformationthat are cognitivelyfamiliar to users. Theintention is
not to modifyexisting applicationswhichcarries the risk of negatingtheir powerand flexibility
but to extendtheir functionality by constructing other components.
3g
Toachievethese goals, an Intelligent Front-End(IFE)wasconceivedas an intricate synthesis
of human-computer
techniques, knowledgemanipulation, data modelmanipulation, user
handlingand the user interface to the possible application¯ In essence,the IFEis a generalised
software environmentwhichdefines the mappingfrom any user’s conceptual modelof a
domainto the data and control requirementsof any targeted application .The IFEis extended
to support co-operative workfor design groups¯ Thesystemincorporates intelligent support,
i.e. co-operativesupporthandlersthat, for example,presentthe informationin a different
variety of media¯
3.4 Co-operative Support Handlers:
Co-operative support handlers are componentsof the IFE and incorporate knowledgeabout
the individualsandthe applications.Theyparticipate fully, or partially, in a designsession
whereindividuals co-operate and communicate
via individual workstations¯ Their roles maybe
of different forms:
¯ they assist the individualsin carryingout tasks; they simplyaid the individualsin
decomposing
the tasks into one or moresub-tasks;
¯ they create fromthe informationsuppliedby the individuals(s) and the supporthandlers, the
description requiredby the application;
¯ they orchestratean applicationagainst the selectedtask andfeeds it with its required
information,
¯ they initiate a designsession, acknowledge
latecomers;
¯ they solve the questions on design session such as whohas control of the application;
¯ they haveknowledge
of different individuals profiles and respondsin the appropriate manner
to ensurethat the designsessionis tailored to their profiles,
¯ they present informationin different types of media;they are responsiblefor choosingthe
best representationto the individuals and interact with themin a waythat maybe different to
the waythey interact with applications;
¯ they supportcriticism of the shared information(representation) of design; such actions
stimulate and improvereflection;
¯ they providesupportin conflict resolutions (whenconflicts are detected) by explainingthe
courseof actions; the resolutions do not haveto be basedon designprinciples; they assist in
generatingalternative answersthat mightcontradict those principles and providea basis for
reasoningaboutthemthat mightbe used in another situation; the mainissue here is that design
has a uniquenessof beingconflictual and uncertain.
4. Frameworkfor Collaborative Design
Theframework
takes into considerationthe use of existing softwareapplications in design.
Tworeasonsinfluencedsucha decision¯Firstly, it is not realistic to take into considerationthe
effort and cost spent in mostcurrent software systems¯ Secondly,while there are many
situations whereapplication designedfromthe outset to take multi-user interaction into
account, it is also appropriatethe case that providingthe designgroups,with only these,
meansthose groupswill be deprivedaccess to manyof their pre-existing tools¯
In remoteworking,there are different levels for whatis being shared. Designgroupsmay:
4O
¯ share the sameview of the sameapplication such as a shared drawingsurface
¯ share the sameapplication and the sameinformationbut it maybe presentedin a
different media
¯ share the samedata, but manipulatedby different applications and hencehavea
different viewof the samedata
(Figure 1) illustrates a framework
for shared applications. Thedialogue handleris responsible,
at the user end, for sharing. Theframeworkneeds to knowthe informationpresented at each
workstation.It enables, and facilitates user preferences.
Themainintention is to developan architecture for mediausagein a collaborative design
system in what (G-reenberg1991) calls personalisable groupware.Anarchitecture whose
behaviourcan be tailored to matchthe needs of groupparticipation, (i.e. each member
of
groupmayobservea different behaviour)and the particular needs of the groupas.a whole(i.e.
each groupmayobserve a different collective behaviour).
G-reenbergillustrates the first point, by an exampleof twoarchitects (one senior, one junior)
in a real time meetingconsultinga client over blueprints displayedover a shared computeraided design (CAD)package. Dependinguponpersonal needs and tastes, each participant
mayrequire a slightly or evencompletelydifferent style of interface. Thesenior architect may
havecompleteaccess to the control of the CAD
package, while the apprentice architect may
only be able to observe the drawing.TheCAD-ware
client maystill be able to gesture and
sketch aroundthe existing drawingthrougha very simplegraphicspencil¯ Illustrating, the
second point, about group differences, the samegroupwaremaybe used by a group of
contractors to implementthe blueprint. In this case, the contractors mayonly be able to
illustrate that part of the drawingthat they are responsiblefor, perhapsto indicate deviations
they had taken from the design.
TheFramework
is an extension of the IFE system. The IFE includes co-operative group
working,that is, users workingas a groupand using applicationsto assist themin their task.
Theintention is developingsuch framework,is to be able to conceptionaliseor personalise it
to the needsof individual withinthe group.
In recent years the developmentof powerfulconcurrent computersand other hardware
environmentshas provokedresearch interest in concurrencyand distribution in AI (Fennell et
al 1977). Anewsubfield of AI, called Distributed Artificial Intelligence (DAI)has emerged
whichconcernedwith the co-operative solution of problemsby a decentralised and loosely
coupledcollection of agents(Daviset ai 1983).. Theagents are able to workin parallel,
that the overall completiontime maybe substantially reduced¯Theapproachesto DAIpoint to
a promisingfuture for real-time systemsfor co-operativeworkin whichthose special
requirements will be accommodated.
Real-time systems have already been developedwhich
haveshownthat DAItechniquesare potentially of great value to applications in real-time
problemsolving ( Nil 1988).
The types of mediacommunicated
within the frameworkmaybe static or dynamicin the form
of text and/or speech(verbal), graphicalimagesand/oranimation(graphical), still pictures
and/or video(pictorial), alarms/bleepsand/ormusic(audio)¯
As design tasks are complex,information used maybe very complextoo. Theuse of
multiblackboardshelps reduce the informationcomplexity.Sucharchitecture dispatches
informationover several blackboardarchitecture, each blackboardcontains relatively small
amountof information. This makesthe systemmoresufficient. Finally, managingmulti-
blackboardsis easier than managinga big single one, because the management
can be spread
over several blackboardhandlers ( Dai et al 1990).
4.1 The Blackboard (BB)
A blackboard is a wayoforganising large amountsof data or knowledgein a mannerwhich
allows different agents to act uponthe data, almost concurrently. Theanalogywith a
traditional blackboardis very strong in that the methodof communication
between
participants in the problemsolvingexercise is via the blackboard.
TheBBacts as a communication
centre for its clients. It stores the informationrepresenting
the current state of the problemas input by the user or inferred by the supporthandler.
Blackboardclients are divided into twocategories: those at the individuals-end(dialogue
handler and user support handlers) concernedwith extracting fromthe individuals the input
and the target definitions, and those at the back-endconcernedwith creating the input and
instructions to drive the application program(s).Theclients within these twocategories
exchangeinformation by meansof separate communicationareas on the blackboard termed
the individuals and the targets areas. Thetwoclasses exchangeinformationby meansof the
mainproblemdefinition area. Themainproblemdefinition area contains the definition of both
the descriptionof the problemand the specification of the requiredtargets.
Clients can also explicitly ask the blackboardfor informationor to keeptheminformedof new
informationposted to any particular area. This avoids clients havingto tell the blackboardand
also serves as a mechanism
wherebytwo or moreclients can create a blackboardas a
communication
channel betweenthem. For example,the user dialogue area is used to pass
informationbetweenthe dialogue and the support handler in order to validate input and
provideessential feedback.
4.2 Dialogue Handler (DH)
The DHis a communicationswitch and a protocol converter sitting betweena communication
mediaand the blackboard. TheDAis responsible for mappingthe data generated by the
communication
mediain the format required by the blackboardand conversely, to mapthe
commands
emanatingfrom the blackboard to semantically equivalent to the communication
media.
It also decides on howbest to present the communication
mediato the individual.
4.3 User Handler (UII)
TheUHtracks the individual’s progress and ensures the systemrespondsin an appropriate
manner.Its function is to set, and, updatethe appropriateuser conceptualisation(individual
type and level of expertise). This ensuresthe subsequentdesign session is tailored to the
individual’s skill level and that the appropriatelevel of guidanceand feedbackor help can be
givenby the support during the session.
42
Applioetione
I
Dedgn Smmion 1
Handler
Dialogue ~_ f
Handler
~.
DeeignHandlarMeeting
Ueer Support
I
BlackboardHandlerI
~
User "~ ( Task "~
Handler J ~ Handler J
U
S
E
R
( Dialogue
~ Handler
~ RI.J,./rA,
J’,.~.n/
~ i TM .......
f
/
~Applicetione~______~
~ Handler
~__~
2
¯
(User
Support
Handler~
(
HDna~er
~
Applioatione
1
DesignHandler8eeeion
1
DesignHandlerMeeting
1
Figure 1. Framework
for Collaborative Design
4.4 User Support Handlers (SH)
TheUSHassist the individualsin carryingout tasks; they simplyaid themin decomposing
the
tasks into oneor moresubtasks.Theyare responsiblefor choosingthe best representationto
the individualsandinteract withthemin a waythat maybe differentto the waythey interact
withapplications.Theysupportcriticism of the sharedinformation
(representation)of design
(Brankiet al 1993);suchactions stimulateandimproverefection. Theyassist in accessing
information,
playersexternalisedesignideas anddesignrelies heavilyonthe ability to recall
ideas. TheUSHaid in associatingideas whichis an importantpart in designthinking. They
assist in choosingthe best suited applicationandthe best interactiontechnique.Theysupport
the expressionof designactions; the expressionis useful for a number
of tasks suchas
explanation,learning,andredesign.Theyprovidesupportin conflict resolutions(when
conflicts are detected)byexplainingthe courseof actions, the resolutionsdonot haveto be
basedondesignprinciples. Theyassist in generatingalternativeanswersthat mightcontradict
those principlesandprovidea basis for reasoningaboutthemthat mightbe usedin another
situation( the mainissue hereis that designhas a uniqueness
of beingconflictualand
uncertain).Theycontrolthe dialogue,collect andvalidateentries, makewhateverinferences
are appropriateandstore themon the blackboard.
43
4.5 Data Handler (DH)
TheDHcreates fromthe informationsupplied by the individuals and the SH, the description
requiredby the application(s).
4.6 Task Handler (TH)
TheTHchoosesthe relevant application with whichto implementthe task.
4.7 Applications Handler (AH)
TheAHorchestrates an application programagainst the selected task and feeds it with its
required information.
4.8 Design Session Handler (DSH)
Therole of the DSHis to initiate and terminate a session, acknowledge
latecomers, support
multiple groupsessions.
4.9 Design Meeting Handler (DMH)
TheDMA
resolves the questions on session control policies such as whohas control of the
application, wholikes control, and howit is passedto other individuals.
4.10 Blackboard Handler (BBH)
Withgroups, Blackboardsare coupledin the systemand are capableof runningconcurrently.
The multi-blackboard frameworkis provided for communicationchannels amongblackboards.
Ifa single blackboardis used, within a DesignSession, it then maybecomea bottleneck.
ASupporthandler mayneed to exchangeinformationin order to co-operate. The role of the
BBHis to conveyinformationfrom one individual workstation to the other. Thepassing of
information is done via the blackboard. TheBBAalso performs information transformation
required by the user support handlersand applications.
Theinformationpresentedto one player is either the sameas the others or in a different
formatdependingon the individual’s choice, as it couldbe inferred by a user supporthandler.
5. Summary
Designis not acted uponby one individual but by manymore.Individuals interact and their
interaction is greater, if not best, in Individualsreasoningprocesses.
Theframeworkproposedis an extension to other workdone on Intelligent Front Ends. The
workof Clarke has been influential. TheFramework,
with its groupworkfunctionality,
supports the use of existing ComputerAidedBuildingDesignapplications.
Withinthe framework
individuals are dynamicallyrelated becausethey learn to reinforce the
conceptsexpressedduring the interaction. Players also introduces newinformation,withoutit
44
there is a risk of reducingthe effectivenessand the creative potential of the relationship. One
majorresearchissue is the handlerdoesnot haveto remaincaptiveof its initial facts and
inferencesprocedures.In this way,it becomesfree of its limitations, and improveits
performanceovertime.
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