Experience Prototyping

Marion Buchenau, Jane Fulton SuriIDEO San Francisco

Pier 28 Annex, The EmbarcaderoSan Francisco, CA 94105

USAmbuchenau@ideo.com, jane@ideo.com

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ABSTRACT

In this paper, we describe "Experience Prototyping" as aform of prototyping that enables design team members,users and clients to gain first-hand appreciation of existingor future conditions through active engagement withprototypes. We use examples from commercial designprojects to illustrate the value of such prototypes in threecritical design activities: understanding existingexperiences, exploring design ideas and in communicatingdesign concepts.

Keywords

Prototyping, experience, design, methods

INTRODUCTION

Increasingly, as designers of interactive systems (spaces,processes and products for people), we find ourselvesstretching the limits of prototyping tools to explore andcommunicate what it will be like to interact with thethings we design.

"Prototypes" are representations of a design made beforefinal artifacts exist. They are created to inform both designprocess and design decisions. They range from sketchesand different kind of models at various levels — "lookslike," "behaves like," "works like" — to explore andcommunicate propositions about the design and its context.

As such, prototyping is a key activity within the design ofinteractive systems. Several groups of designers andresearchers, perhaps most notably at Apple Computer,Xerox Parc, and Interval Research, have been active bothin pushing the boundaries of prototyping beyond the rangeof traditional methods [1,2] and in developingunderstanding of the value of different forms of prototype.For example, Houde and Hill [7], discuss various functionsfor prototypes as being essentially about the "role" anartifact will play, its "look and feel" and how it will beimplemented. Other work has explored issues such asdifferent levels of fidelity [17], prototypes for differentaudiences [5,16] and models for use in the context ofparticipatory design [4,12]. Further, prototyping as a

design practice is now promoted within the businesscommunity as a key element in innovation [10,13].

Building from this foundation, designers at IDEO areworking to expand internal prototyping practices toembody the concept of "Experience Prototyping" as anintegrated part of the design process. In this paper we willdiscuss what we mean by Experience Prototyping, whywe think it is important and then look at its applicationwithin three key design activities — understanding,exploring and communicating — through examples fromdesign projects.

What is "Experience Prototyping"?

First, let’s think for a moment about what we mean by"experience." Experience is a very dynamic, complex andsubjective phenomenon. It depends upon the perceptionof multiple sensory qualities of a design, interpretedthrough filters relating to contextual factors. For example,what is the experience of a run down a mountain on asnowboard? It depends upon the weight and materialqualities of the board, the bindings and your boots, thesnow conditions, the weather, the terrain, the temperatureof air in your hair, your skill level, your current state ofmind, the mood and expression of your companions. Theexperience of even simple artifacts does not exist in avacuum but, rather, in dynamic relationship with otherpeople, places and objects. Additionally, the quality ofpeople’s experience changes over time as it is influencedby variations in these multiple contextual factors.

With respect to prototyping, our understanding of"experience" is close to what Houde and Hill call the "lookand feel" of a product or system, that is "the concretesensory experience of using an artifact — what the userlooks at, feels and hears while using it." But experiencegoes beyond the "concrete sensory." Inevitably we findourselves asking questions about the "role" which Houdeand Hill define as "the functions that an artifact serves in auser’s life — the way in which it is useful to them." Andeven more than this, when we consider experience wemust be aware of the important influences of contextual

factors, such as social circumstances, time pressures,environmental conditions, etc.

By the term "Experience Prototype" we mean toemphasize the experiential aspect of whateverrepresentations are needed to successfully (re)live orconvey an experience with a product, space or system. So,for an operational definition we can say an ExperiencePrototype is any kind of representation, in any medium,that is designed to understand, explore or communicatewhat it might be like to engage with the product, space orsystem we are designing. Obviously this can includedesign prototyping techniques such as storyboards [15],scenarios [14], sketches [17], video, or step throughMacromedia Director™ simulations, all of which certainlyadd value by communicating elements that make up anexperience. But they do this to a mainly passive audience.For the sake of this paper we wish to focus on themethods and techniques which support active participationto provide a relevant subjective experience.

In discovery, there is a continuum that extends from beingtold about something, seeing for yourself, to doing ityourself. Quoting the Chinese philosopher Lao Tse:"What I hear I forget. What I see, I remember. What I do,I understand!" When we use the term "ExperiencePrototyping" we are talking about methods that allowdesigners, clients or users to "experience it themselves"rather than witnessing a demonstration or someone else’sexperience. One of the basic tenets of the concept is thatexperience is, by its nature, subjective and that the bestway to understand the experiential qualities of aninteraction is to experience it subjectively.

Experience Prototyping is less a set of techniques, than itis an attitude, allowing the designer to think of the designproblem in terms of designing an integrated experience,rather than one or more specific artifacts.

Why is Experience Important? Why Now?

More and more we find ourselves designing complex anddynamic interactions with converging hardware andsoftware, spaces and services — products such as mobiledigital communication devices, or systems of connectedinteractions such as those which occur on a train journey oran Internet shopping spree. The resulting hybrid artifactsrequire new expressions of their original qualities, such as"sensitive product behaviors" based on true hard/softintegration. This unknown terrain demands new designapproaches, specific considerations and, ultimately, thedesign of integrated and holistic experiences set incontext, rather than of individual artifacts or components.For example, it demands that the designer think about the

experience of light rather than think directly about thedesign of the physical lamps themselves. To meet thisdemand, the designer needs to focus on "exploring bydoing" and actively experiencing the sometimes subtledifferences between various design solutions.

Multiple disciplines are needed to solve the designproblems of today — e.g. interaction design, industrialdesign, designers of environments, human factorsspecialists, mechanical and electrical engineers. Eachdiscipline brings a unique understanding of the issues athand and an individual approach to solving them [8]. Towork effectively as a design team it is important todevelop a common vision of what the team is trying tobring into being. Therefore, it is a powerful asset to havetools and techniques which create a shared experience,providing a foundation for a common point of view.

Information becomes more vivid and engaging when itresonates with personal experience. If designers and clientscan have informative personal experiences, it is easier forthem to grasp the issues and feel greater empathy withboth the people who will be affected by their decisions,and the experiences users may face.

The tools we use to design, such as prototypes, influencethe way we think. Solutions, and probably evenimagination, are inspired and limited by the prototypingtools we have at our disposal. We have observed ourselvesthinking in new ways about what is possible when newmaterials or design tools become available — such ascomputer based drafting (changing the developmentprocess to become more iterative), virtual 3D modeling(influencing the formal design towards more organicshapes), and new materials — such as Teflon™ or electro-luminescent fabrics (offering new product functions andopportunities for product design). Experience Prototypingallows us to engage with new problems in new ways.

EXPERIENCE PROTOTYPING IN PRACTICE

We have identified three different kinds of activitieswithin the design and development process whereExperience Prototyping is valuable:

• Understanding existing user experiences and context

• Exploring and evaluating design ideas

• Communicating ideas to an audience

In this section we will explore how ExperiencePrototyping contributes to the activity and give someexamples from design practice.

Understanding Existing User Experiences

Experience Prototyping here is applied to demonstratecontext and to identify issues and design opportunities.One way to explore this is through direct experience ofsystems — the prototyping goal is to achieve a highfidelity simulation of an existing experience which can’tbe experienced directly because it is unsafe, unavailable,too expensive, etc.

The questions to ask in this stage are: What are thecontextual, physical, temporal, sensory, social and cognitivefactors we must consider as we embark on design? What isthe essence of the existing user experience? What areessential factors that our design should preserve?

The following three project examples will further explainand illustrate how Experience Prototyping can unveil thenecessary insights to answer such questions.

The Patient Experience

This example builds upon people's own imaginations andthe use of proxy devices to recreate the essential elementsof a personal experience that would not otherwise beavailable.

The project was to design product and service relatedelements for an Internet enabled cardiac telemetry system.The system would involve both face-to-face and remotedoctor-patient interactions as well as automated supervisionfor patients with chest-implanted automatic defibrillators.Before embarking upon design solutions for the futuresystem, the team wanted to know what systemcharacteristics would be needed to ensure as positive anexperience for patients as possible. What is it like to be adefibrillating pacemaker patient? What is it like notknowing when and where defibrillating shock will occur?How does that affect people’s everyday life? The designteam set up circumstances to produce a similar experiencefor themselves to that currently endured by patients withsuch implants. As a real first-hand patient experience wasobviously not feasible, one of the team set upcircumstances to produce a similar experience. The aimwas to provoke insights into important functional andemotional issues and inspire thoughts about how to dealwith them.

The designer distributed pagers to all other team members.The pager signal was to represent a defibrillating shock thatwould be of sufficient impact to knock a person off theirfeet. Participants were paged at random times during aweekend and asked to capture their immediatecircumstances for each occasion — where they were, withwhom, what they were doing and what they thought andfelt knowing that this represented a shock? After this

exercise, team discussion about personal experiencesranged from anxiety around everyday activities likeholding an infant son or working with power tools, tosocial issues about how to communicate to onlookers whatwas happening and how to get proper medical help.

Figure 1: The patient's experience kit. When participants werepaged this indicated that they had received a defibrillating shock;they recorded their surroundings with the camera, and noted theirimpressions.

The participants, including engineers, bio-technologists,and representatives from marketing and product planningon the client side, quickly translated their own experiencesinto patients' needs. For example they appreciated theimportance of warning information to help patientsanticipate and prepare for a shock. They also saw the needto provide information to indicate the patient's conditionto bystanders, and a broader base of remote support for thisnext generation of products and services.

Clearly, the form of prototype devised by this designerwas based upon some initial assumptions about the fact thatsurprise, social and contextual factors would be importantelements of the experience. This type of insight,sometimes informed by research of a more conventionalkind, is necessary to guide the design of a specificExperience Prototype so that it can simulate importantaspects of the real user experience, unveiling thepreviously not-fully-appreciated design issues.

The ROV Pilot Experience

This example too, used a proxy device to provide theteam with specific insight into an experience that was notreadily available to them.

The project involved the design of a pilot’s interface for anunderwater remotely operated vehicle (ROV) and its

cameras. It was important that designers grasp and dealwith some of the cognitive confusion that would arise forthe operator. There would be problems for operatorssteering a tethered vehicle with six degrees of freedom, aswell as multiple cameras — which can be positionedindependently from the ROV itself — while trying tofind a target in a vast undifferentiated space with limitedvisibility.

In the initial project phase, the design team created a taskanalysis, based on interviews with pilots and literatureresearch which was useful to them, but did notcommunicate the realities of ROV operation veryeffectively. For the first experience prototyping exerciseone of the designers used a rolled-up sheet of paper tolimit her peripheral view while searching for a target — aPost-it note in her work space.

To get to the more problematic cognitive and functionalissues, the team developed a game in which one player,A, stood in a room which was empty except for multiplechairs (portraying underwater obstacles), and one of themheld a chocolate bar, the target. Player A held a videocamera connected by a long cable to a remote TV screenwhere the live picture was viewed by player B. Player Bgave verbal instructions to player A to move right/left,forward/back, and up/down and gave separate verbalcommands to direct the camera.

After a few yards of cables wrapped round A's legs and thechairs as well as B's frustration at making mistakes— "Aargh! I meant camera right not move right," thedesign team and the client had personal insight about manyimportant issues. For example, it was obvious that a criticalneed was clear feedback to support a mental picture of thevehicle’s path through space, feedback about the tethercondition, and the need for a clear distinction betweencontrols for the vehicle and for the camera.

As a follow-up, the team asked a participating retiredROV pilot about the validity of the simulated experiencewhich, to his surprise, portrayed a quite accurate picture.He provided additional information, mainly aboutcontextual factors (e.g. different levels of experience,underwater conditions, support tools like maps) whichmight change or influence the portrayed experience. Theability to share this Experience Prototype providedverification and enrichment of the simulated experiencewith a real life event. This further enhanced theparticipants' understanding of the pilot's problems, andcreated a shared reference point between all members ofthe design team as the work moved forward.

Role Playing a Train Journey Experience

It can be very informative, as well as fun, for designers toexplore what experiences would be like for a particularperson in a particular context through dramaticimprovisation. This might be with or without propsrepresenting designed artifacts. In this example, aninvestigation into passenger needs for a new rail service, agroup of designers used acting techniques such as roleplaying, bodystorming and improvisation to gain deeperinsights. These methods are inspired by work at IntervalResearch [1,2] where the terms "informance" (forinformative performance) and "bodystorming" (forphysically situated brainstorming) were invented todescribe these contextually rich explorations.

Improvisation seems to be most useful when acted out in asequence of focussed scenes to ensure that appropriateactivities and contextual situations are covered. In this trainjourney example, the design team explored different typesof travelers, their needs, and various unexpected situationsduring specific stages of a train journey (e.g. entering thestation, ticketing, waiting, riding the train, connecting toother means of transportation). Each scene was introducedwith a card containing the scene’s rules, explaining thegoal, and the roles of players and audience. A professionalactor familiar with improvisational theatre techniques actedas the supervising moderator. He gave one playerinstructions such as "Buy a return ticket for yourself and achild", while another designer played the role of aticketing machine. Other instructions involved differentconditions: "Now do it with gloves on." "It’s dark andwindy." "The machine only takes coins, no notes." "Theticket machine is very helpful and friendly."

Taking breaks for discussion after each scene enabled thelearning to be captured immediately following eachimprovisational scene. Such breaks are a time for groupreflection and idea generation stimulated by actuallyparticipating in or witnessing the scene. The breaksprovide an opportunity to go beyond appreciating theissues involved to generating initial design ideas. Inbodystorming — brainstorming that occurs either during orbetween scenes in response to problems that are uncovered— many ideas are expressed verbally but some areexpressed physically and come spontaneously throughinteraction with proposed design elements, or quicklyimprovised stand-ins. In our example, the improvisation ofthe ticket machine interaction might cause someone toprovide a shelf for a purse or luggage, or a radical change ofappearance such as indicating that the machine is out oforder (e.g. turning away from the intending purchaser).

The dynamic physical nature of the event stimulates anappropriate response in situ.

In a second piece of research for the same design task, theteam took a train journey themselves. To facilitate theexploration of unusual situations and to open the designers’minds to other customer experiences, they found it helpfulto devise and assign specific tasks to each other. They gaveeach other cards that read, for example: "Pretend that youcan’t speak English." "Be hungry, find something to eat.""Be friendly and chat to the train staff."

Figure 2: Experiencing a train journey. The team combinedobjective passenger research with subjective discovery as theyplayed out roles they assigned each other.

This exercise bridges the gap between real and prototypedexperiences. It was a "real setting with real people," butthe designers' feelings and behavior were mixed withperformance and acting. The designers found that role-playing in the real setting gave them permission toobserve. It also provided a useful additional lens throughwhich to observe and live passengers' experiences in thecontext of their own train journeys.

However, the key idea in both these role-playingexperiments, as with the simulations described in the firsttwo examples, is to have the designers make discoveriesthemselves. These discoveries have a level of personalsignificance that makes them easy to understand and discussamong designers and users. The vividness of this ownedexperience creates subjective, lasting memories whichinfluence and guide the designers’ choices and decisionsthroughout all stages of the design and developmentprocess.

Exploring and Evaluating Design Ideas

The main purpose of Experience Prototyping in thisactivity is in facilitating the exploration of possiblesolutions and directing the design team towards a moreinformed development of the user experience and thetangible components which create it. At this point, the

experience is already focused around specific artifacts,elements, or functions. Through Experience Prototypes ofthese artifacts and their interactive behavior we are able toevaluate a variety of ideas — by ourselves, with designcolleagues, users or clients — and through successiveiterations mold the user experience.

Controller for an immersive environment

In the early stages of developing a user experience,multiple design directions need to be efficientlyprototyped and compared. Ad hoc use of analogous objectsas props can quickly guide decisions about which kind ofexperience is most appropriate. In this example, ofdesigning a control device with six-degrees of freedom fora video game, the team identified three radically differentpotential directions and looked for props to help themunderstand the kind of experience each would afford:

• A tactile immersive experience — represented by apalm-sized pebble

• A shared experience, where the control functionscould be split between two hands or two players— represented by two different-sized joysticks mountedon suction pads

• A full-body physical experience— represented by thesurface of a customized skateboard.

Simply "playing" with these relatively crude props was apowerful method, enabling the designers to unveil thenuances and implications of each particular direction.

Figure 3: Control in an immersive video environment. Early inthe project, the team played with a range of everyday objects toexplore what different levels of physical involvement might feellike.

Experiencing an Airplane Interior

The same concepts apply in exploring ideas at a completelydifferent scale, when designing a user experience set in apublic and/or constrained environment. This exampleinvolves early exploration of ideas for the interior layoutand components of an airplane. The design team togetherconducted a variety of bodystorming explorations within afull-scale foam-core environment simulating the inside ofan airplane. Using props, such as chairs, readily available inthe studio, the team enacted various social situations andactivities such as sitting and reading, sleeping, and talkingto a travel companion, receiving and eating meals, toevaluate ergonomic and psychological comfort withdifferent arrangements.

Again, many ideas for physical configurations could betested in a time and money efficient manner. Additionally,the involvement of the whole design team created acommon focus and a shared ownership of the designdirections chosen for further development.

Figure 4: Bodystorming layouts for an airplane interior. Ideaswere generated and evaluated rapidly by the team as they directlyexperienced physical and social issues in this full-scaleenvironment.

TV Channel Changing Experience

Sometimes it is important to engage clients and other teammembers in radical design ideas before they are fullyresolved. In this example, for an exploration of televisionremote controls, the designer wanted to explore thespecific experience of switching channels, while ignoringother aspects of functionality or look and feel. He wasespecially interested in exploring the implications of amore intuitive and multi-sensory design solution. Hecreated what he called "behavioral sketches" which weresimple electronic circuits containing a few lines of code

(Basic Stamps™), encased in off-the-shelf soap dishes. Thetwo experience prototypes were controlled by a tiltinggesture, switching channels up or down. The twoprototypes differed however, in their feedback, one beingvisual — through moving light bands, the other beingtactile using vibrations. By tinkering with the simplesoftware program, he was able to efficiently develop andtest many subtle iterations of product behaviors and userexperiences. The low resolution and fidelity of theprototypes proved to be vital for successfully sharing theinsights of this conceptual approach with other designersand the client. They were expressive enough to convey avery sensual and compelling control experience, withoutconstraining the imagination for further fine-tuning of theuser experience, or the transfer to product applicationsbeyond remote controls for televisions.

Children's picture communicator

Part of the process of design exploration involves checkingout ideas with potential users. For example, in the EECfunded "Maypole" project's exploration of communitycommunications [11] the goal was to create prototypeswhich would give children an experience as close aspossible to that invoked by the intended design solution.Usually, user tests focus on fairly specific functionalperformance issues. Such tests also generally involveconditions that are not typical of the ultimate use situation,for example they frequently involve outsiders (e.g. asobservers or "Wizards of Oz" when some functions needto be simulated by a person). This makes it difficult toanswer questions about experience such as: How willpeople feel about the system we are designing? Will itchange the way people behave or think about an activity?Is it compelling to them in their own context? A trueExperience Prototype for users — providing a reallyrelevant experience — seems to require a level ofresolution and functionality such that it can be "let loose"into an everyday context and more fully integrated intopeople’s lives.

For the Maypole project, Nokia built working sets ofpicture communicators that the design team was able todistribute to children who could take them away and playwith them unsupervised for days at a time [6].

Figure 5: Picture-communicating prototype. Despite heavybackpacks containing batteries and drivers for the prototypes, thechildren were happy to integrate picture-sending and receivinginto their daily activity.

These prototypes required a power pack and transceiverunit that the children had to carry around in a backpack,yet the experience of being able to take pictures and sendand receive them to and from friends proved so compellingthat the users almost forget about that inconvenience.

As an observer of user evaluations, one knows very quicklyif the designed experience is a good one. If it is, peopleget so involved in the experience that they forget aboutthe limitations of the prototype (e.g. a tether to thecomputer, or an extreme weight or size hindrance becauseof limiting prototyping components).

Communicating Ideas

The role of Experience Prototyping here is to let a client,a design colleague or a user understand the subjective valueof a design idea by directly experiencing it. This is usuallydone with the intention of persuading the audience — forexample, that an idea is compelling or that a chosen designdirection is incorrect.

Digital Camera Interaction Experience

In an early project on digital photography the goal was tohelp a client envision what digital photography might beand how to design both the camera and the userexperience as a complete system (including picture storage,retrieval, manipulation, etc.). In the initial phases of theproject the team used traditional communicationtechniques such as scenarios, still and dynamicvisualizations, and interactive on-screen simulations. Aftergoing through a series of presentations, the design teamrealized that the client did not completely understand theintended user experience and camera behavior. Thebreakthrough came when the designers built a hardware

and software integrated "look and feel" prototype based onthe design specifications as they stood at that time. Theprototype bore little resemblance to a desirable product inshape, form, size or weight. For example, there was asizeable cable running from the camera to a desktopcomputer where all the processing occurred.

This Experience Prototype contained a small video cameraattached to a small LCD panel, encased in a box. The sizeof the LCD panel was determined by the desiredresolution, rather than by the desired physical size, in orderto maintain the key aspects of the proposed userexperience. The working prototype was accompanied byan appearance model to communicate the appropriate sizeand detailed formal aspects of the design solution.

Figure 6: Digital camera interaction architecture proto type. Theprototype used a desk-top computer's processing power tomanipulate the dynamic qualities of the control system andscreen behavior.

The prototype had a live video feed and captured stillphotos with audio annotations in real time, as responsetime was a critical component of the user experience.Since the processing was done by the desktop computerrunning regular software with a simple programmingenvironment, it was easy to fine-tune the response time ofthe camera to enable the design team and the client to feelthe impact on the user experience.

It was the clients' developers who asked for multiple copiesof the prototype which were then used as a "livingspecification" throughout the clients' internal design processto maintain a perspective and verify new design concepts.The client reported that there were many pressures tochange the resolution, or the speed of response, but thatthe prototype enabled them to see, feel and resist thenegative impact of such changes.

Figure 7: Kodak Digital Science DC 210 . This was the first ina series of Kodak digital cameras which embodied theinteraction architecture and response qualities illustrated by theExperience Prototype.

This example perfectly demonstrates the importance ofmotivating and exciting a decision-making audience byproviding them with a stimulating, hands-on experience.Knowing the audience and their expectations helpsdetermine the resolution and fidelity of a prototype. Alsocare needs to be taken to explain its specific intent whenan audience is not familiar with this particular form ofprototyping. In this digital camera example, the designteam built the Experience Prototype with enoughflexibility for it to endure many iterations of refinementon the way towards the desired user experience. Thedesigners were creating a prototyping platform where thehardware components were carefully chosen and built tolast. The software environment was established in amodular architecture, so that simple code changes wouldnot affect the artifact’s behavior in other modes. The clienthowever, was so impressed by the hands-on experience,that some of the design details which were compromisedby time pressure, were ignored and the design phase wasannounced as completed directly following thepresentation!

The Kiss Communicator

In this last example, "getting into the mood" became asignificant set-up task for successfully communicating theproposed experience.

The "Kiss Communicator" was a concept prototype builtto explore ways of using technology to communicate withanother person in a subtle, sensual way. The intention wasto keep the nature of the physical object as simple aspossible, so the interaction was more about the experienceof the message.

Designed to facilitate the exchange of emotional contentbetween people separated by physical distance, the "KissCommunicator" used wireless technology to transmit thedigital equivalent of a personal gesture, such as a wave,wink or a kiss. Each Communicator connects only with aspecific corresponding module, resulting in a secure andintimate one-on-one exchange. To let a partner know thatyou are thinking of her or him, you squeeze theCommunicator gently. It responds with a slight glow toinvite you to blow into it and create your "message" in theform of an animated light sequence as the device respondsto your breath. The "message" shows while you blow andif you are happy with it, you simply relax your grip and itis sent to the corresponding Communicator. On the otherend, the partner Kiss Communicator indicates that there isa message but waits until its owner squeezes it to play backthe light sequence.

There are some important conditions necessary to reallyappreciate the experiencing of this prototype: an intimaterelationship, two distant people, sending a gesture, etc.Now imagine sharing this concept with clients in theirbusiness suits in a conference room. To help set the scenefor the experience in this formal context the designersnow usually preface the hands-on experience of theprototype with a short video sequence which shows a pairof the devices being used by a dreamy couple who areworking apart. Using conventional devices like soft focusand a romantic soundtrack, the video creates, at leasttemporarily, an atmosphere that is more appropriate. Thissituation exemplifies how traditional and more passivecommunication techniques (like video) and ExperiencePrototypes can work hand-in-hand, with the goal ofsharing a new user experience with an audience.

Figure 8: The Kiss Communicator. This pair of prototypes letpeople have the hands-on experience of creating, sending andreceiving subtle sensual messages. Video helped to create anappropriate context.

CONCLUSIONS AND NEXT STEPS

Our current analysis and examples have shown howexperience prototyping has contributed to real designprojects in three key ways:

• By helping to develop understanding about theessence or essential factors of an existing experience:Experience Prototyping simulates important aspects ofthe whole or parts of the relationships between people,places and objects as they unfold over time.

• In exploration and evaluation of ideas: ExperiencePrototyping can provide inspiration, confirmation orrejection of ideas based upon the quality of experiencethey engender. It produces answers and feedback todesigners’ questions about proposed solutions in terms of"what would it feel like if...?"

• In communication of issues and ideas: by enablingothers to engage directly in a proposed new experienceit provides common ground for establishing a sharedpoint of view.

Experience Prototyping is not a new phenomenon withinthe design community; designers have always been readyto adopt and adapt technology and processes of many kindsto create early representations of their ideas andunderstandings. But the concept of ExperiencePrototyping specifically, we believe, deserves a consciousfocus. It should become an established and well-supportedtradition within design practice. This belief is foundedupon observation of our own practices that shows that wecan be more sensitive, can design better experiences forpeople, and can be more convincing about the value of ourdesign decisions, by intentionally adopting such anapproach.

From this perspective, it is obvious that ExperiencePrototyping is not about the creation of a formalizedtoolkit or set of techniques, but is about developing anattitude and language to solve design problems.

Establishing an Attitude

Traditional prototyping techniques and tools are embeddedin traditionally distinct design disciplines. ExperiencePrototyping, as a tool in designing complex systems, asksfor a blending of the multiple design disciplines andbeyond. One great advantage of Experience Prototypingis that it requires hybrid and overlapping skill-sets such thatit is not exclusive to any single design discipline. As such,it offers an opportunity for all types of designers tosupplement their traditional discipline skills in an effectiveand broadening way.

Initially at least, it seems important to promote a low-fidelity mindset for Experience Prototyping. High-fidelity

prototypes certainly have their place but our examplesshow that, especially in the understanding, exploring andevaluating design phases, there is great value in low-techmethods and improvisation with basic materials — rolledpaper, pagers etc. Low-tech solutions seem to promote theattitude that it is the design question that is important, notthe tools and techniques that can be brought to bear. Basedon what we have learned so far, we plan to furtherdevelop a range of skills among our designers includingtools and techniques such as Basic Stamps™, PIC chips(supported by traditional tools such as MacromediaDirector™ and simple electronics to integrate hardwareand software), improvisational theater and role-playing,basic video/audio recording and editing as well as themore traditional physical modeling such as foam models andfoam core environments.

Different activities need different kinds of spaces andresources. We are currently in the process ofsupplementing our traditional model shop and electricalengineering lab with a large flexible space — a "theater"— to function as a stage for spontaneous role playing, as aplace to build "scenes" and full-scale environments, andprovide audio/video recording, editing, and projectionfacilities, as well as blue screening capabilities. In additionto the functional value these spaces and facilities have insupporting Experience Prototyping, they also provideimportant value in physically representing the attitude theyintend to promote. They are a daily reminder to push theirspecific design projects and their specific disciplines to alimit, and to sustain and evolve the language of ExperiencePrototyping.

What We Don’t Know

As we move into a more conscious frame of mind aboutExperience Prototyping, we are aware of much we do notyet understand about how to best utilize the principles forthe most innovative and successful results.

What is the appropriate representation for differentaudiences? Experience Prototypes might be designedprimarily for ourselves, other members of the design team,users, and internal or external clients. Theaudience influences both the type of prototype we createand the degree of context and explanation we provide toframe the experience for them. For users it may bedifficult to provide an early, low-fidelity improvisationprototype of sufficiently robust nature that they can havean experience in a naturalistic context without supervision.Higher levels of fidelity have their problems, too. As inour example of the prototyping platform for the digitalcamera, clients may become unshakably attached to earlyideas when they experience a single convincing

manifestation of many different possibilities and perceiveit as the final solution. Clearly it is important for designersto share their understanding of the intent behind anExperience Prototype, but perhaps there are also lessons tolearn about communicating these intentions moreeffectively by carefully choosing the prototype orprototyping technique.

A second question concerns the relationship betweenactive and passive prototyping methods. Intentionally, thispaper focuses upon prototypes that create an active/first-hand rather than passive/vicarious way of appreciatingexperience. Hence we discuss the value of role-playingand improvisational theater, rather than of watchingsomeone else's experience. Is there any danger that activeinvolvement, especially when an audience is present, tendsto direct energy away from understanding the experienceto acting as if you were having the experience? Perhapssometimes there is at least additional learning to be gainedby observation and reflection of someone else having anexperience as opposed to being fully immersed in ityourself and then transferring or generalizing your ownpersonal and subjective experience without cross-checkingwith real users. The example of the ROV operator'sfeedback following the prototyping experience, the use ofsupporting materials for the digital camera experienceprototype (the designers provided an appearance model asa "looks like" reference) and the video scenarios explainingcontext for the Kiss Communicator, shows that there is abalance to be found in effectively combining active andpassive ways of realizing experience.

Indeed, it is essential to think of Experience Prototypingas complementary to other design methods. First, nomatter how good Experience Prototyping is at promotingempathy, (e.g. as in the patient experience) we cannotactually be other people. There will always be a place forother design and research methods to help us understandother people's points of view. Second, as in all forms ofprototyping, we inevitably make choices about whatelements of the ultimate experience to represent and whatto omit. This means recognizing that a single prototype isnever enough. Multiple prototypes, and other methodssuch as contextual observation, user testing andparticipatory design all bring important perspectives tocomplete the picture.

Additionally, these other methods help us in identifyingthe relevant factors of an experience that we plan torepresent. For example, in a specific prototype, just whatmix of emphasis do we want to give to specific aspects ofthe experience, such as sensory, physical/spatial, cognitive,social and temporal/dynamic qualities? To create an

appropriate prototype we need to determine, for example,whether we are interested primarily in the sensory andtemporal/dynamic aspects of an experience (such as in theTV remote), the physical/spatial and social aspects (as inthe airplane), or the cognitive and temporal/dynamicaspects (ROV; digital camera). And, since we aredeveloping only partially integrated prototypes, "settingthe stage" for the experience becomes crucial. We need tobe explicit about what needs to be ignored (e.g., becauseit "does not look like" or "would not be tethered") andabout what context surrounds the user experience ("a highpressure emergency situation" or "a very intimate andprivate moment").

Finally, we come back to the point that people'sexperiences with products and systems are a complexintegration of personal and circumstantial factors. Peoplewill have experiences with the things we design, whetherwe intend them or not, and in ways that we cannot hopeentirely to predict. Nevertheless, understanding, exploringand communicating the experiential aspects of design ideasare central activities in design. Experience Prototyping,while it creates only approximate and partial simulations ofthe real experiences others will have, brings a subjectiverichness to bear on design problems. It is an approach that,we believe, will benefit from more conscious attentionand deliberate experimentation.

ACKNOWLEDGMENTS

We are grateful to many colleagues and peers in theinteraction design community for their contributions to thispaper, whether through example or critique. Specificallywe wish to thank and credit the following IDEO designerswhose attitudes and inventions have inspired the ideas, aswell as provided the examples, presented in this paper. Inorder of appearance:

Patient experience: Leon Segal

ROV pilot experience: Marion Buchenau, David Gilmoreand Mike Mills

Train journey experience: Graham Plumb, Maura Shea,Laurence Arcadia, Josh Rubin and IDEO San Francisco

TV channel changing experience: Duncan Kerr

Control experience for a video environment: GrahamPullin, Tracy Currer, Frances Samalionis and Paul South

Experiencing an airplane interior: Colin Burns, MartinBontoft and IDEO Europe

Children's picture communicator: Alexander Grunsteidl,Thomas Stegmann, Alison Black and Nokia Research Center

Digital camera interaction: Matt Hunter and Duncan Kerr

Kiss communicator: Duncan Kerr, Heather Martin and MatHunter

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