From: AAAI Technical Report SS-02-08. Compilation copyright © 2002, AAAI (www.aaai.org). All rights reserved.
Functional and Formal Reasoning in Architectural Sketches
Ellen Yi-Luen Do
DesignMachineGroup
Department
of Architecture,Universityof Washington
Seattle, WA98195-5720
ellendo@u.washington.edu
arguments hold true especially in the domain of
architecture wherethe tool of the trade is drawing(Doand
Gross 2001).
Weare interested in building computational tools to
support design reasoningthroughthe interface of freehand
sketching. In this paper, we first report our research on
empiricalstudies of design drawingsin both the functional
and formal aspects. Wethen describe somecomputational
tools built to support designing. Finally, weconcludewith
discussionsandpossible future researchdirections.
Abstract
Architectsuse different symbols
andconfigurations
in their
drawingsto explorealternatives and to communicate
with
each other. Theyuse sketchesto performfunctional and
formalreasoningin their designprocess.For example,
when
thinking about spatial arrangements,they drawbubble
diagrams;whenthinkingaboutnaturallighting, theydrawa
sunsymbolandlight rays. Thispaperreports the findings
fromempiricalstudiesof drawingsandreportsthe software
systems that were implementedto support intention
inference and automatedactivation of knowledge-based
designtools to supportdesign.
Studies
Why Study
Design
Drawing
of Design Sketches
Wehave conductedseveral empirical studies on design and
drawingto determine whether, and to what extent, it is
possible to infer, interpret, or evenguess whata designer
was thinking about by looking at the drawingshe has made.
Weare interested in howdrawings get made, and what
specific knowledgeand reasoning process they represent.
Specifically, we are concernedwith the thought processes
that underlie the operations comprising a drawing.
Therefore,these empirical studies were conductedfocusing
on design problem solving with form or function,
separately.
The studies include 1) data analysis of 62 architecture
students’ concept diagramming,2) video transcripts and
protocol analysis of four architects conductingdesignof an
architect’s office, and 3) a retrospective analysis of
pavilion house design that was carried over the period of
15 years byan architect.
In the early design process, designers drawdiagramsand
sketches to explore ideas and solutions. Drawingsare
mental tools. Architects sketch to help themselvesto see
and understand the form they work with, and to
communicatewith others. Despite the fact that these
drawings may seem crude, they are valuable in
understanding how designers work because each of them
serves its purposein a workof importance.Eachline in a
drawingplays a role. It couldrepresent an outline of a form
or a path of force (e.g., wind, rain, or light ray).
Architecturaldesign deals with both formand function.
The activity of drawing includes both seeing and
thinking about the subject being represented. Design
drawing is an iterative and interactive act involving
recording ideas, recognizingfunctions and meaningin the
drawings, and finding new forms and adapting them into
the design (Goldschmidt 1991; Sch6n and Wiggins 1992;
Suwaand Tversky 1996). It serves as external symbol
systems to facilitate thinking and support emergentideas
(Goel 1995; Fish 1996; Mezughi1996).
Recently we have seen research workand computational
systems to support sketching in various domains(Hearst,
Gross et al. 1996; Stahovich 1996; Landay and Myers
2001). For example,a user can sketch widget symbolsfor
interface design (Landay1996)or military course of action
planning (Forbus, Fergusonct al. 2001). Theyargued that
electronic sketching tools provide designers focus on the
task at hand,on spatial relations andstructure of the design
instead of specific detailed look and feel of the drawing
(Ferguson 1992; Landay and Myers 2001). These
Functional Reasoning
The first study used design stories and diagrams from a
case-based design aid called Archie (Kolodner 1991;
Domesbekand Kolodner 1992; Zimring, Do et al. 1995).
The database library of Archie contains stories, problems
and responses from post-occupancy evaluation data
collected in field studies of ten courthousesand libraries.
All related items are cross-linked. Eachparticipant were
given the tasks of makingdiagramsfrom stories, writing
stories fromgiven diagrams,pairing diagramsand stories,
and commenting
on existing Archiediagram-storypairs.
The second study involved protocol analysis of four
designers in action. The designers were first given a
37
programbrief of an architect’s office space design. After
reading the design program,designers were asked to start
with a newsheet of paper (or tracing paper) for each task
and to focus on four different concerns in conceptual,
schematicdesign. The tasks include 1) spatial arrangement,
2) lighting, 3) visibility andprivacy,and4) fitting a special
piece of furniture into the design.
Fromthe diagrammingexperiment (Do 1995) and design
protocol analysis (Do 1997) we found that designers use
graphic symbolsto represent certain physical objects and
design tasks and concerns. For example, when thinking
about spatial arrangementsof functional spaces, designer
would draw bubble diagrams to represent the rooms and
their connections. They also drew graphic symbols for
furniture objects to put themselvesin the context of the
design problems.Whenthinking about lighting concerns, a
designer woulddrawa configuration consisting of an arrow
penetratinga vertical rectangle, representinga light ray in a
sectional view. Figure 1 showsexamplesof the diagrams
drawnby the participants.
Formal Reasoning
The third study is a retrospective analysis of the pavilion
house design drawing. Over the course of 15 years, the
architect had been engagedin formal manipulationsof the
designfor a residenceand archivedall the drawinginto six
CD-ROMs.
Welooked at 110 drawings selected by the
architect and developeda coding schemeto classify these
drawingsinto different categories. This study resulted a
conceptual frameworkto account for connections among
the drawings(Neiman,Doet ai. 1999). Ourstudy attempts
to identify relationships betweendrawings in order to
understandthe role of formal reasoningin a design process.
Whatbeganas a thought experimentresulted in a range of
plausible interpretations to account for what might have
actually happened in the design process. The
interpretations were madethrough several iterations of
sorting, classification and coding. Theresults werelater
comparedwith the designer’s retrospective examinationof
the drawings.
I.Iootrmnq~
(E7)
(Ell Pipe
Body
box1|61
IF.d) Chirnneyh~
’~F-l:nkl
~ eacmYm’*)
R15) Hernial sgtlpa, ~===- ilk
~ me (E’I4!
co~rnn~t)
(EI~,)Ve~lcu
window
Wall(E2)
Figure I. Drawingconventions:(a) bubblediagramfor spatial
arrangement,
(b) graphicsymbolsfor furniture layout, and(c)
lightingconcernsin sectionalview.
Designersalso wrotetext to label the functions or names
of the space. Whenthinking about fitting a piece of
furniture in a conference room, designer wouldnot only
drawgraphic symbolsfor furniture but also dimensional
markers and numbersto reason about dimensions.
P 4* I0-40
bufferfor table
40*2=80
section Iff
3" lff-~T
ffi
37’ = .......
!_
©onfcrcflc¢
room
~.- ..-D 20’’10’
,,2(X)~l.
Figure 2. Dimensionalreasoning for spatial arrangement
accordingto programsquare footage requirements(numbers,
markersandcalculations)
For example,a participating designer drewdimensional
markswith 10’ intervals along the length of the site (three
1 O’s and a 7’). Thenhe checkedto see if the table couldfit
into the conferenceroom(20"10). First he wrote downthe
dimensionof the table (4"10), calculated and wrote down
the answer40, and doubledit (80) for buffer space. Figure
2 shows the drawing and annotations of the reasoning
process derivedfrom the verbal protocol.
38
Figure3. Principalarchitecturalelementsfor the PavilionHouse
(withcodingfor elementtypes).
Manyof the drawings are composedof more than one
drawingand consist a compositionof plan, sectional, or
isometric viewsof the floor plan, or study variations of a
fagade. Wedivided the compositedrawingsinto individual
drawings and coded them with unique identifiers and
drawing properties. The schemecodes properties of the
drawings such as the elements depicted as well as
projection types and viewangles of the building. Figure 3
showsthe common
architectural elements and their codes
(in parenthesis, e.g., El represents a column, and E2
represent a wall). Figure 4 shows a drawing coded of
elementtypes, location and mediumused.
ID#
PI-30
CPl-9a)
P2-16
P2-15)
Drawing
Elements
El, E2, E3,
E4, ES, E6,
E7, ES, E9,
El0, El2,
El2, El2,
El2, El2,
El3, El4,
El5
Location
/scale
Medium
pencil
MI)
~ciiow,
blue, red
markers
M4)
Figure4. Adrawing
in codedtable of differentclassifications.
For any two drawings, the coding schemealso accounts
for the transformations of the design elements such as
geometrictranslations of shapes, locations and color. The
letter codes E, L, T, and C correspond respectively to
elementidentifiers, location identifiers, and transformation
types, and C specifies the use of a color. D indicates the
projection type, V the view direction, Mthe drawing
medium,and I the designer’s self-described intention in
makingthe drawing. For example,the expression
E 16@L4->(T4+T I+T 17) ->@L9
indicates that the designelement#16(staircase) at location
#4 (middle left) movesdown(transformation #4), moves
right (transformation#1) and rotates 180" (transformation
#17) to location #9 (lower right). If there is
transformation (transformation #17) of the location (L9:
lower right) of element #16 between two drawings, it
wouldbe codedas
E 16@L9->(T16) ->@]..9
The East Building was designed to extend space for
programming and to act as complement to the West
Building. It was a design task to provide not only
organizationand functional needs,but also to fit in a noneregular (trapezoidal)site with strict restrictions of setback
lines fromthe surroundingstreets and aesthetic principles
(symmetry,
axis, etc).
.... .... ..,,j~" -"
. ~ .... i~,e ¯ Tt’~! !i
~L~
: _ ..,.::]. _~-~.,~ ~._sdjo-o--b--ewjo~6
~ ---~__
:’~i
Figure 5 showsthree design drawings, the 3x3 location
grid, and the expressionsof transformationsof the staircase
between them.
’
L -..,.:.’ .,.:.’.. ¯ L] I;
"
"
~" ’~
.....
11
e
........
9,t,
"
’t
.I IF~I
Figure6. Site plan for the EastBuildingNationalGalleryof Art
(drawnafter (Galleries1978))
The early design concepts kept in Pei’s notebook or
diary showsconcerns about the axis of the WestBuilding
(Figure 6, left), and extendingit to divide the trapezoidal
lot into severaltriangles, as shown
in Figure7 (tight).
E16 0L4 -> (T4+Tl+T17) -> 0L9
E16 0L9 -> (T16) -> 0L9
Figure5. Staircase(El6) in drawingI (left) is moved
0"4:down,
TI: right, andTI7:rotate 180)to a differentlocation(from1.4
Lg) in drawingII (middle). The location of the staircase
identicalbetween
drawingII (middle)anddrawingIII (right)
codedas transformation
TI6 (no transformation).
Drawing Evolution
Figure7. Concept
sketch,site analysis,and spatial arrangement
(drawnafter (Galleries1978))
in Design Process
The notion of design being the fusion of form and function
is widelyacceptedand followedin the field of architecture
and industrial design (Meikle 1979). The dictum ’Form
follows Function’ was first introduced by the architect
LouisSullivan (Twombly
1986) in 1896to explain that his
building design follows natural law. Later Miesvan dcr
Rohefurther argued that ’Form IS Function’, and many
modernistarchitects and designersshare this notion. There
are often debates about whetherform precedes function or
vice versa (Janson 1982; Anderson1987). However,it’s
the commontraining and education of architects that
successful building should incorporate form and function
together.
The East Building of National Gallery of Art designed
by I. M. Pei is a goodexampleof howconceptual drawing
evolves to account for the form and functional
arrangementsof the building. Figure 5 showsthe final
drawingof the building on site. The original National
Gallery of Art, or the West Building is a symmetrical,
rectangular, neoclassical building with a rotunda in the
middle.
39
Examining Pei’s design drawings from a formal
perspective reveals that the shapes or the formare tightly
connectedto the functionof the spaces. At first glance, the
drawingsin Figure 8 sharesimilar shapes and structure.
Theyall have triangle components.The three drawingson
the right are actually fromfacing pagesof the notebook.
o
Figure 8. Designdrawingsfromthe design notebook.(after
(Galleries1978))
The first sketch on the left is a very simple diagram
showingtwotriangles, one isosceles and one right triangle
The second sketch is muchmore elaborate. The motif of
triangles has becomepatterns coveting several areas. The
final building uses the triangle pattern for the space flame
abovethe concoursethat connectsexhibition space and the
Center for Advanced
Study. The form of triangle serves the
purpose of functional support for the frame. The third
sketch is diagrammatic. Each circle represents an
independent museumas noted in the notebook (Galleries
1978), and connected to the bottom right triangle with
another triangle. The last sketch shows the symmetric
feature of the WestBuilding, and each gallery has a prism
shapeand is connectedby bars.
Figure 9 contains a series of diagrams explaining the
developmentof the East Building from preliminary concept
stage to the final conception realized in the building.
Besides obeying the setback guidelines and specific
stipulations from the" urban agencies, Pei projected the
longitudinal axis of the West Building to bisect the
building lot. Usingthe axis as a guide, a symmetricalline
that is diagonalon the site is drawnand dividesthe lot into
twoessential spaces. Oneis the isosceles triangle, facing
the West Building and echoing the symmetricalgeometry.
Theother spaceis a right triangle. This formal arrangement
solves the problemof the site; at the sametimeit provides
functional space for two programmingrequirements. The
isosceles triangle is usedfor exhibition galleries, and the
right triangle is the Center for Advanced
Study and other
scholarly and administrative functions. These two
functional spacesare connectedby a triangle concourse,an
atrium with skylights. The three comersof the isosceles
triangle becamegallery towers connectedby bridges.
Figure 9. Design evolution: (1) axis extended from West
Building,and setbacklines, (2) diagonaldivides2 spaces,
isosceles triangle and a right triangle, (3) comersof isosceles
triangle becameexhibition towers, and (4) the right triangle
became
the Centerfor Advanced
Study.(alter (Galleries1978))
(right) derived from the 2Dplan (middle). Note also
concept sketch on the left of Figure 10: though crude,
several shapes and lines are identifiable. Thebottomright
angle is circled and connected with bubbles for more
developmentof the courtyard schemefor the Center of
AdvancedStudy. Figure 11 shows a pair of the East
Buildingdesign with similar shapes but different details.
This is similar to the findings from the Pavilion House
study. Designers move, rotate, and transform design
elementsin their drawingto makeformal arrangements.It
is worthnoting that in this case, the transformationof the
drawingelementsinvolves functional arrangementsas well.
(Wemaybe able to further verify this if we can capture
design rationale and verbal protocols of the wholedesign
process.)
Figure11. Thelocationof the openingor courtyardfor the Center
of Advanced
Study(ocoupying
the right triangle at the bottom)
are differentin these twodesignsketches.Theopening
onthe left
schemeis on the south side, whilethe drawingonthe right has
the opening
fi’omthe slopeof the triangle.(after (Galleries1978))
Computational Tools for Sketching
Stories of howthese drawings account for the design,
and the solving of aesthetic and engineeringdecisions are
abundant (Wiseman1990) (Art; Galleries 1978).
descriptions of form and function in design development
are usually inter-connected, Besides the evolution of
architectural drawings in the design process, someother
drawings also shed light on what actions designer take
whenthinking about design.
Figure10. (1) Concept
sketchof the buildingwithfight triangle
circled and called out. (2) Designof the Centerfor Advanced
Studywithcourtyard.(3) Isometricdrawingof the volume
for the
Centerfor Advanced
Study.(a~er(Galleries1978))
The first exampleis the moveor projection from twodimensional floor plan drawing to three-dimensional
isometric drawing. Figure 9 showsa 3D isometric drawing
4O
Recognizingthat it is possible to associate symbolsand
spatial arrangements in a drawing with the designer’s
intention, or task context, we have implemented
computational tools to use freehand sketching as an
interface to intelligent systemsfor design. Thesedesign
tools include using diagrams for knowledgeand image
retrieval, building performancesimulation, and threedimensional modelmakingfor early stages of design (Do
1998; Gross and Do 2000).
At the most basic level of symbolic processing, our
systemscapture stroke data fromthe tablet and use the pen
path and stroke features (speed, comer,aspect ratio, ere)
identify symbolsdrawnby the designers. A symbolcould
be a single-stroke glyph, or consisted of multi-strokes
glyphs. A low-level recognizer starts the processing and
display recognition upona pen-up action. Designers can
also turn off the recognition display, or ask the background
processor not to resolve ambiguoussymboluntil further
information is given that helps the programidentify the
context. Resolving ambiguousintentions is necessary
because the same drawing symbol could mean different
things in different context (Gross and Do 1996). For
example, a circle on a floor plan could mean a column
while a circle outside and abovea building section with a
line penetrating the building envelopewouldbe the sun and
light ray. Similarly, a circle with alphabet neighbors is
likely to be an alphabetOwhilea circle next to a numberis
likely to be the numberzero. A higher-level recognizer
deals with analysis of spatial relations amongdrawing
symbols and the combinationthereof. For example, a big
circle surroundedby small squares on a floor plan could
meana dining table set. Figure 12 showsthat the wigglyline placed directly below an horizontal line can be
recognized as a symbol for the "ground," thus set the
contextinto ’section.’
Im
m
I--zN
I M~~u~
~
m,
.
kllkim
k ° .
m~
N
D
Figure 14. Whena ’monitor_glare’intention is recognized,
(bottomleft) a message
prompts
the user (topleft) andit activates
a WebBrowser(fight), requestsa keyword
searchandthe search
returnsa list of relevantinformation
N~
Figure12. A"ground"symbolis composed
of a horizontal line
anda wiggly-line(left). Thenamesof the elementsare replaced
by the newnameof the configuration(andsets the contextto
’section’)
The Right-Tool-Right-Timemanageridentifies context
based on existence of special symbolor configuration to
trigger an intention recognizer. Oncedesign intention is
recognizedin the drawing, the systemwouldautomatically
activate the appropriate tools for the task at hand. For
example,Figure 13 showsa visual analysis programcalled
Isovist (Do and Gross 1997) can be activated once the
Right-Tool-Right-Time
programrecognizes the intention of
’view’. The viewpoint and lines are translated into the
programfor simulation.
Figure13. A ’view’intention is recognizedin a ’plan’ context
(top) andthe drawing
is translatedinto walllines (fromlines)
a viewpoint(arrowsand circle) and sent to the Isovist visual
simulationprogram(bottom).
Another example uses the intention and context
information derived from the drawingto activate keyword
search on a web search engine or a database. Figure 14
showsthat an intention of "monitor_glare"is recognizedby
seeing the configuration of a computer(monitor and hard
drive) and a sun ray (sun symbolwith arrowindicates light
direction). This intention activates the browserto launch
keywordsearch using a website. The sameinteraction can
be applied to other knowledge-basedsystems, a slide
library, or a case library like Archie.
41
A common
task in design is dimensional reasoning and
calculation of area footage. Drawing symbols of
dimensional markers and numeric operators can be
recognizedas a context of ’calculation’ and thus activate a
calculator for designer. Figure15 showssuch interaction.
b~
O
, ~mms mmml
~r.~m mam~
r
Figure15. Aconfiguration
of numbers
andarithmeticmarks(left)
is recognizedas an "adding" intention (middle) and RTRT
activatesa calculator(right).
The Back of an Envelopeproject and the Right-ToolRight-Time manager demonstrate that a pen-based, or
calligraphic interface can be used in a variety of domainsin
design process. Designers can use freehand sketches and
diagrams to index and retrieve databases or to activate
knowledge-based information systems and simulation
programs.It is a frameworkof knowledgecapture. Onecan
use the graphic recognition of the systemand add to the
frameworkmore modules and functionality to support
design. Belowwedescribe two newsketching interfaces for
supportingformal and functional reasoningin architectural
design: I) GIDA- GraphicsInterpreter of DesignActions,
and 2) VRSketchpad- an interface for creating instant 3D
worldsby sketching.
GraphicsInterpreter of DesignActions
Withthe coding schemedevelopedfor the Pavilion House
analysis, we are currently working on a Graphics
Interpreter of Design Action - GIDAto managedrawing
comparisonand sorting of the diagrams. The GIDAsystem
allows a user to diagramover a picture underlayof design
drawingand to generate an analysis of the drawingitself
and its relationships with other drawings. For example,a
diagram’stopological and geometricrelations amongparts
of the drawingcan be recorded and used in comparisonto
another diagramtraced from a different design drawingto
reveal the spatial transformations amongthe elements.
Figure 16 showsa pair of design drawingstraced from the
Pavilion Housefagade study. The GIDAsystem lays out a
3x3grid over the drawingand generates a list of occupied
cell numbersfor each object.
D
element from first drawingto the second one(addition of
grid cell 3). The table showsthat the Hoodelement in
Drawing#1 is removedfrom Drawing#2. Likewise, the
transformation of the ChimneyBoxis a movingdownfrom
(4 5 4) to (7 4 5 8
VR Sketchpad
In VRSketchpad(Do 2001) we developed a simple sketch
recognition systemthat inferred three-dimensionalmodels
fromtwo-dimensionalsketches. The idea is to use drawing
to construct virtual built spaces. Our current prototype
systemenables a designer to drawa floor plan with walls,
columns, and furniture elements and the programproduces
a 3D model in VRML(Virtual Reality Modeling
Language).Figure 18 showsthat any froehand sketch can
be convertedand extrudedas columnsand wall partitions.
i’
¯
| :
F
Figure16. GIDA’s
locationidentifier (3x38rid) overtwodesign
drawings
In the exampleof Figure 16, Drawing#1 (Figure 16 left)
has nine elements and Drawing#2 has eight. Each element
has a position in the global coordinatesystemand a list of
the local grid cell sequence.Figure 17 is a table showing
the list of elements for each drawing and their
correspondingcell sequence.
Ekmtmlt
Drawing#1
T~ekWall
ChinmeyBox
Chi~ Pipe
V-wmd~,v
I
V-window
2
V-window
3
Hood
H-~ip1
H-ship 2
H-strip3
H-stamp
4
(7456987)
(,454)
(14)
(69)
(51)
(4 7)
(6 3 2)
(45 6)
(456)
Drazemg ~
(741236987)
~4587)
(14)
(369)
Figure18. Curveshapesand lines (leR) are extrudedto make
partitionsin a VRML
world(right).
The recognition engine of the systeminterprets drawing
symbols(e.g., circles and lines) with designer intended
object representations (columns, walls) and diagram
configurations(e.g., dining table and chairs). A designer
can also drawarrowsto indicate locations of interests and
therefore define a viewingpath into the 3Dworld (encoded
as viewpoints into a VRML
world). A designer can also
define a configuration of symbolsto represent furniture
objects as shownin Figure 19. By sketching the furniture
layout in diagrammatic form with arrows indicating
specific viewpointsand view angles, designer can produce
a 3Dscene in an instant and the visitors can follow the
guidedpath to explorethe virtual space as designed.
(456)
(45 6)
(456)
(789)
Figure17. State of drawingelementsrepresentedas list of cell
sequence.
Transformations between drawings can be inferred by
comparingthe lists of the sameelements from different
drawings. For example,the cell sequencelist of V-window
1 was changed from (6 9) to (3 6 9). The bounding
sizes of the elementin the twodifferent drawingsare very
close. This describesthe shifting-uptransformationfor this
42
4b ~r
Figure19. Furniturelayoutsketch(TV,couch,dinningtable set,
columns,andwalls) creates 3DVRML
scene(righOwith objects.
Discussion
Sketchingis important in the early, conceptual stages of
architectural design. Therefore,computationaltools should
support sketching activities. The empirical studies
examined intentions in and relations among design
drawings. Our prototype systems demonstrate how
freehand drawing interfaces can support analysis and
design. Theseare all part of a larger researchagendaon the
role of drawingfor design support. Manyissues are worth
exploringfurther.
The act of drawingis a form of design reasoning. An
architectural design involves both functional and formal
reasoning. Designdrawingsuse lines and geometricshapes
to represent natural or manmadeartifact such as building
components and plants, phenomenasuch as sound and
light, humanbehaviorsuch as sight and circulation, as well
as boundariesof spaces. Thestudies of design students on
the conceptdiagramming
exercise and the protocol analysis
of architecture design reveals promising results for
computational tools to support sketching. Wefound the
designers drawdifferent symbolsand configurations when
thinking about different functional design concerns.
Onthe other hand, our exploratorystudy of the Pavilion
Housebroadenedour understandingof the formal role that
drawings play in design. Design sketches are made of
geometricshapes. Notsurprisingly, aesthetic principles and
formal expressions also influence howa designer works.
From the study we found that a designer manipulates
design objects through transforming shapes and locations,
changingviewpoints, drawingtypes, and mediato explore
design alternatives. Whenfunctional concerns are easy to
solve, these form manipulations involve the search of
implicit graphical law or convention. For example, the
balance of the configuration, its symmetrical or axial
considerations,aspect ratio of the object and proportion,all
serve as criteria for design manipulation, or or moves.
Transformations are applied to previous designs to
generate alternatives and to predict the outcomesof new
proposal. The designer manipulates the visualized
representations to evaluate the consequencesof design
moves. These manipulations are simply geometric
transformations but in combination the process becomes
complex.Wefound that designers play mental gameswith
themselves. They play by defning rules, selecting
strategies, making design movesfrom the rules, and
evaluating and discovering the outcome. These design
moveschange the shape, dimensions, orientations, and
placementsof the design elements.
If a design process always involves fusion and
interchanging activities of both functional and formal
aspects, then how might we find the appropriate
interpretations of the design intentions expressed in
drawing?Are there specific symbolsthat can be identified
to indicate the right context?Theseries of design drawings
of the East Building reveal that designer moveback and
forth from functional to formal concerns fluently. The
geometric shapes are manipulated first for formal
arrangements such as symmetryand establishing axial
lines. Thenthese shapes are read as symbolarrangements
for functional spaces. The ingeniouspart of the design is
that all problems, be they functional or formal, are all
solved and evolvedthroughthese architectural sketches.
In summary,we conclude that we can view the act of
drawingas manipulationsof symbolsthat represent internal
functional and formal knowledge. Understanding
architectural sketches are not an easy test. Laboratory
studies can isolate formal or functional problems
separately. However,in a real life seeting, these issues
mingle and are dealt with at the same time. To make
computationaltools really support sketching activities in
design, we would need to study more howdesigners move
betweendifferent modesin a real design task. Observing
and analyzing design protocols could probably help
identifying howdesigner operates. Maybethe transitions
amongvarious states, the sequence of drawing, are the
external controls of the environment representing the
mentalimage.It is clear that the activity of drawingcan not
be detached from seeing, and thinking about the subject
being represented. Wecan not drawan object or a scene
unless wesee it before us whetherin real physicalworld,or
in mind’seye. Manytimes, the drawingsare created from
adopting and adapting objects from memory or
imagination. Therefore, using drawing to accessing
databases or knowledge repository is definitely an
important issue. Analyzing and understanding what
sketches represent is important. However,there is still a
broadarea to explore in order to understandhowsketches
are made, and why are they made, to support what
activities.
Acknowledgements
Thematerial in this paper is baseduponworksupportedby
the National Science Foundationunder Grant numbersIIS96-19856 and IIS-00-96138. The views and findings
containedin this materialare those of the author and do not
necessarily reflect the views of the National Science
Foundation.
References
Anderson,
S. 1987."TheFiction of Function."Assemblage
2:1831.
Art, NationalGallery.http://www.nga.gnv/.
Do,E. Y.-L. 1995. What’sin a diagramthat a computershould
understand. In CAAD
Futures ’95: TheGlobalDesignStudio,
Sixth InternationalConference
on Computer
AidedArchitectural
Design Futures. M. Tan and R. Teh. Singapore, National
Universityof Singapore:469-482.
Do, E. Y.-L. 1997. Computabilityof DesignDiagrams-- an
empirical study of diagramconventionsin design. In CAAD
Futures97, R. Junge.Munich,Kluwer:171-176.
Do, E. Y.-L. 1998. The Right Tool at the Right Time Investigation of FreehandDrawingas an Interface to Knowledge
BasedDesign Tools. Ph.D. Thesis, Atlanta, GeorgiaInstitute of
Technology.
Do, E. Y.-L. 2001. Graphics Interpreter of Design Actions: the
GIDAsystem of diagram sorting and analysis. In CAAD
Futures
2001. B. d. Vries, J. P. v. Leeuwen
and H. H. Achten.Eindhoven,
KluwerAcademicPublishers: 271-284.
Do, E. Y.-L. and M. D. Gross 1997. Tools for Visual and Spatial
Analysis of CADModels - implementing computer tools as a
meansto thinking about architecture. In CAAD
Futures 97. R.
Junge. Munich,Kluwer: 189-202.
Do, E. Y.-L. and M. D. Gross 2001. Thinking with Diagramsin
Architectural Design. In Artificial Intelligence Review. A.
BlackweU.Dordrecht, The Netherlands, AcademicPublishers:
135-149.
Domeshek,
E. and J. Kolodner1992. A case-based design aid for
architecture. In Artificial Intelligence in Design’92. J. S. Gero.
Dordrecht, Netherlands, KluwerAcademicPublishers.
Ferguson, E. 1992. Engineering and the Mind’sEye. Cambridge,
MA,MITPress.
Fish, J. C. 1996. HowSketches Work- A Cognitive Theory for
Improved System Design, Doctoral Thesis. Loughborough
University of Technology.
Forbus, K. D., R. W. Ferguson, et al. 2001. "Towards a
Computational Model of Sketching." In Intelligent User
Interfaces: 77-83.
Galleries, AdamsDavidson1978. I. M. Pei &Partners, Drawings
for the East Building, National Gallery of Art. Its Evolution in
Sketches, Rendering, and Models1968-1978. Washington,D.C.,
Exhibit Catelog.
Goel, V. 1995. Sketches of Thought. CambridgeMA,MITPress.
Goldschmidt, G. 1991. "The Dialectics of Sketching." In
Creativity ResearchJournal v.4(# 2): 123-143.
Gross, M. D. and E. Y.-L. Do 1996. AmbiguousIntentions.
Proceedings, ACM
Symposiumon User Interface Software and
Technology(UIST’96). Seattle, WA:183-192.
Gross, M.D. and E. Y.-L. Do2000. Drawingon the back of an
envelope. In Computersand Graphics, Calligraphy Interface. J.
A. J. a. E. Glinert. NewYork,PergamonPress. 24: 835-849.
Hearst, M. A., M.D. Gross, T. F. Stahovich, J. A. Landay.1996.
"SketchingIntelligent Systems."IEEEIntelligent Systems13(3):
10-19.
Janson, H. W. 1982. Form Follows Function - or Does It?
Modernist Design Theory and the History of Art. The
Netherlands, Maarsen.
Kolodner, J. L. 1991. "Improving human decision-making
throughcase-baseddecision aiding." ,41Magazine
12(2): 52-68.
Landay, J. A. 1996. SILK: Sketching Interfaces Like Krazy.
HumanFactors in Computing,CHI96. T. V. Program.
Landay, J. A. and B. A. Myers2001. "Sketching Interfaces:
TowardMore HumanInterface Design." IEEE Computer34(3):
56-64.
Meikle,J. L. 1979. Twentiethcenturylimited: industrial designin
America,1925-1939.Philadelphia, TempleUniversity Press.
Mezughi, M. M. 1996. The Integral Role of Drawing in
Architectural Conception.Ph.D. Thesis. GlasgowSchoolof Art,
MackintoshSchoolof Architeeture, University of Glasgnw.
44
Neiman,B., E. Y.-L. Do, and M. D. Gross. 1999. Sketches and
Their Functions in Early Design: A Retrospective Analysis of
Two Houses. Design Thinking Research Symposium’99. W.
Porter and G. Goldschmidt.
SchSn, D. A. and G. Wiggins1992. "Kinds of Seeing and their
functions in designing."DesignStudies 13(#2): 135- ! 56.
Stahnvich, T. F. 1996.SketchIT:a Sketch Interpretation Toolfor
Conceptual Mechanical Design. Artificial
IntelLigence
Laboratory. Ph.D. Thesis. Cambridge, MA,Massachusetts
Institute of Technology.
Suwa, M. and B. Tversky 1996. "WhatArchitects See in Their
Sketches: Implications for Design Tools." Proceedings of ACM
HumanFactors in Design’96 (CHI’96): 191-192.
Twombly,R. C. 1986. Louis Sullivan : his life and work. New
York, Viking.
Wiseman,C.1990. I. M.Pei: a profile in Americanarchitecture.
NewYork, H. N. Abrams.
Zimring, C., E. Y.-L. Do, J Kolodner and E Domeshek.1995.
Supporting Case-Study Use in Design Education: A
Computational Case-Based Design Aid for Architecture.
Computingin Civil Engineering, A/E/C Systems ’95. J. P.
Mohsen.Atlanta, GA,AmericanSociety of Civil Engineers. II:
1635-1642.