Human-Centered Design Method for Serious Games: ABridge Across Disciplines
ABSTRACTHuman-centered design (HCD) is often considered a cen-tral, largely unquestioned, tenet of good practice for productdesign. However, while various manuscripts had been pub-lished on HCD methods for generic interactive systems, fewdiscuss HCD method for interdisciplinary projects; specifi-cally, serious games (designed for a primary purpose otherthan pure entertainment). Applying HCD to the design ofa video game, we soon found that there were missing linksin the reviewed methods. Through the development of ourserious game, an educational computer game to prepare firsttime parents for childbirth and labor, we propose a new HCDmethod We show how iterative design, evaluation, and test-ing must take into account the interdisciplinary requirementsof creating serious games. It is necessary to receive inputsfrom all of the different fields of experts before initiating thedesign stages: the thematic experts as well as the game de-sign experts and learning experts.
Author Keywordsmethod, design, serious games
ACM Classification KeywordsH.5.2 Information Interfaces and Presentation: MiscellaneousOptional sub-category
INTRODUCTIONHuman-centered design (HCD) and its variations, such asparticipatory design, reflective design, and cooperative de-sign, is an approach to design that attempts to actively in-volve the end users in the design process to help ensure thatthe product designed meets their needs and is usable. Al-though the practice varies slightly depending on the methodchosen, the approach usually entails users participating dur-ing several stages of an innovation process: they participateduring the initial exploration and problem definition bothto help define the problem and to focus ideas for solution;during development, they help evaluate proposed solutions.HCD, more specifically participatory design, also has the no-tion that users are experts in their own domains. A continu-
Submitted for review to CHI 2011.
ous stream of publications reported the success of productsdesigned using user-centered design (UCD) method, result-ing in greater buy-in from their target users, making HCDa central, largely unquestioned, tenet of good practice forproduct design.
While various published manuscripts had provided tremen-dous help for practitioners that plan to adopt the HCD methodwhen designing traditional computer applications, few re-ports discussed UCD for non-standard computer applicationssuch as serious games. Serious games are defined as gamesdesigned for a primary purpose other than pure entertain-ment, although to be faithful to the idea of games, they stillhave to be entertaining, engaging, and fun while servingtheir primary purpose (e.g., education, persuasion, and reha-bilitation). Because of the nature of serious games, they gen-erally encompass several domains. Generally, the science ofgame design is one of the necessary domains, and makes upthe game rules, win conditions, core mechanics, and gameaffordances (what the player is allowed to do). The theme(or themes) of the game compose the bulk of the gamescontents and these can be from very diverse domains such ashealth, education or psychology. The interdisciplinary na-ture of serious games can be suspected as the main cause ofthe lack of proposed UCD method for their system design.
In this paper, we present published manuscripts on HCDs forgeneral product design as well as for video games. We re-viewed and attempted to apply various HCDs and when wedeveloped our serious game, an educational game for firsttime parents to prepare them for childbirth and labor , andrealized that there were missing links in each of the methodswe tried. Throughout the development process of our seri-ous game, we discovered these missing links and narroweddown the stages of the development that worked best in ourserious game project. We present our proposed developmentmethod, with several characteristics that are different fromother methods we reviewed. The most distinctive differenceis that the stages of conceptual design and implementationare not discrete.
RELEVANT WORK: MODELS OF SYSTEM DESIGNSince the introduction of ISO 13407 standard for the human-centered design process , various other methods had beenproposed. The following sections describe various HCD meth-ods that informed our work.
Figure 1. The ISO 13407 standard for human-centered design
The ISO 13407 standard for the human-centered design pro-cess defines five stages (see Figure 1) .
1. Identify need for human centered design;
2. Specify context of use;
3. Specify requirements;
4. Produce design solutions;
5. Evaluate designs; and finally, depending on the result ofevaluation,
6. The system satisfies specified requirements, indicating thatthe design and implementation process is over and theproduct can be released.
The phases are meant to be completed in this order. If theevaluation finds an error in the system or a need for furtherdevelopment, the designer proceeds back to step 2, specify-ing again the context of use. This very generic approach isa starting point for many projects in computing; however, ithas been shown that engineers do not work in this manner.Designers analyze the design much more often than is sug-gested by the ISO standard, and move in unpredictable waysaround the graph .
Star Life CycleThe star life cycle  is a well-established HCD design prin-ciple for interactive systems. Figure 2 shows the stages in thestar method. The phases are as follows.
1. Requirements specification
3. Conceptual design and formal design
6. Task analysis and functional analysis
The phases are not meant to be visited in any particular order.The designer starts at any node and passes through evalua-tion on the way to any other node. For example, after gath-ering requirements, the designer evaluates the requirements
Figure 2. The star method of design, with evaluation being the keycentral component
prior to generating a formal design. Next, the designer eval-uates the formal design and generates a prototype.
The star life cycle has two drawbacks for our project in se-rious games. First, it does not provide the designer with aclear starting point. On the contrary, it suggests that the de-signer start with whichever outside node is most appropriate,with little guidance of what constitutes an appropriate stage.Although some designers start with task diagrams, other de-signers may prefer to start with a conceptual design; stillothers prefer gathering requirements. This creates a problemfor the designer without sufficient information about the do-main of the system, as in the case of serious game. It leavestwo questions: Is implementation a valid starting node? Canprototyping be a first step along the design cycle? Proba-bly not, as the designer typically does preliminary research,draws concept art, or defines requirements prior to imple-menting anything. Second, the star life cycle is a general-ized design-development paradigm for the human-computerinterface. We soon found that for the design of our seriousgame, the model lacks the ability to embed interdisciplinaryand team work effort.
Fullertons MethodFullerton, et al.  extend the user-centered system designto video games, and suggest three phases of design and de-velopment:
2. Prototyping; and
The phases are to be completed in this order, but the phasesgenerate a cycle, with conceptualization following play-testing.Conceptualization refers to the overall design of the gameand its mechanics. Prototyping involves making low- orhigh-fidelity versions of the game and its implementation-level details. Prototype versions are typically progressivelymore detailed versions of the game, incrementally incorpo-rating features, aesthetic elements (such as graphics and sound),and game complexity with each version. Finally, play-testingrefers to user interaction with the game. Users play the game
Figure 3. The method of video game design presented by Fullerton, etal., and modified by Rankin, et al.
and rate it based on several metrics, including but not lim-ited to playability, enjoyment, engagement, ease of learning(for a game with a learning component), and so on. Becauseuser-centered game design requires frequent interaction withusers, the three phases are often revisited, and hence, theprocedure becomes iterative. Feedback from the users is in-corporated into the next prototype.
Rankins MethodRankin, et al. propose a modified-Fullerton framework forserious games, as social interactions, learning, and play areall involved . The diagram is shown in Figure 3, over-layed with Fullertons proposed method of game design. Afirst phase, called observational studies, is added before con-ceptualization can commence. The four phases according toRankin are
1. Observational studies;
3. Prototyping; and
In the observational studies stage, the game designer definesa purpose for the game and observes the social situationsin which learning occurs. During conceptualization, the de-signer formulates the games overall mechanic and aesthetic.The results of prototyping give an early version of the gameand allow the designer to quickly collect a range of user andexpert feedback about the game. The designer can also ad-minister a pre-test during this phase of design [3, 11]. Fi-nally, user feedback is collected during play-testing. Thedesigner administers the post-test, and based on the results,modifies the specifications for the game in preparation forreturning to the conceptualization phase of design.
Components of Video Game Design for LearningA design method for video games should be mindful of theelements of video game design. Dondlinger reports the keyelements for an educational game to be as follows .
1. Edutainment vs. educational games
3. Narrative context
Figure 4. Learning hierarchies
4. Goals and rules
5. Interactivity and multisensory cues
The main difference between edutainment and an educationalgame is the where the games mechanics lie on the repetitionabstraction continuum. Games in the edutainment categorystress memorization and repetition. Educational games al-low the player some free will and choice; they encouragethought, and hope to engage players on a deeper level oflearning. Further, Dondlinger reports that there are three hi-erarchies for learning: skills, deduction, and abstract think-ing. These are shown graphically in Figure 4. Skills canbe learned by rote memorization, and regurgitated upon re-quest. An example is the multiplication table or state capi-tals. Deduction and hypothesis testing is a learning outcomein which players can form hypotheses as a result of play-ing the game. More complicated game-play is required, asplayers must be given the ability both to make decisions andto make mistakes. For example, a game that teaches electro-magnetism through simulation may teach players about elec-tromagnetism in a physics class. Finally, the deepest level isabstract thinking. In this learning outcome, the player canapply skills and methods learned in-game to situations out-side of the game.
Next, the designer must consider the motivation for play.What will keep the player interested in playing? The playermust be given just enough praise to be interested in playingfurther, but not too much to make the game seem to easy. Inother words, the challenge level of the game must be appro-priate to the audience, and the feedback appropriate to thechallenge level.
The narrative context refers to the story. What is the settingof the game? What is its history? The game should be tellinga tale to entertain and engage the player, as if it were an in-teractive book, complete with details about the environment.
The goals and rules of the game include the games affor-dances (what the player is allowed to do in the game world)as well as game rules, scoring, win and loss conditions, andother game mechanics elements.
Finally, interactivity and multisensory cues refers to inter-face design and player feedback. The game designer con-siders the input and output devices as well as the sensorystimuli both to the game and to the player.
APPLICATION OF RANKINS METHODIn making a serious game to teach women and their part-ners about the stages of labor, the physiological changes ofcervical dilation, and different ways to help a woman in la-bor, originally we applied Rankins model to our design anddevelopment cycle.
Observational StudiesAccording to Rankin, observational studies is a phase ofthe design cycle in which the designer conducts backgroundwork prior to formulating a game concept. The designer ob-serves people playing video games and the social interac-tions that emerge. During this stage, it is crucial to take noteof the social aspects of playing video games as well as themethods of learning.
Because The Prepared Partner, a birth partner training game,was very specialized, it was difficult to find people play-ing such a game to observe. We had to replace observa-tional studies by thoroughly researching the subject area oflabor and childbirth. More specifically, we extracted themesfrom texts designed to prepare expectant parents for laborand childbirth. These themes included, but were not limitedto, the progression of labor (stages of labor), ways to inducerelaxation during labor, reducing anxiety and fear, and othernatural ways to handle the discomfort and pain associatedwith labor
In addition, to gain an insight into preparation methods forchildbirth and to gauge interest in a childbirth video game,we had to conduct an online survey. A convenience sampleof 120 participants, both male and female, was used. Par-ticipants had given birth to at least one baby, or had partici-pated as a support person in their partners birth experience.We found that 4% of participants claim to have preparedfor childbirth by playing video games. However, we knowthat no video game preparation methods were in existenceat the time of the survey; hence, we conclude that resultsfrom these preparations were negligible. We found that 5%of participants would have liked to prepare for childbirth byplaying a video game, and would do so if they could go backin time and prepare for their first child again. Only 3% ofparticipants would recommend such a method of prepara-tion to their friends. The results of the survey suggested thata niche market could develop for a childbirth-themed videogame focused on educating the birth partner.
As between 50% and 80% of expectant parents attend child-birth preparation classes [9, 1] we attended such a class atthe local birth center to better understand how parents pre-
Figure 5. Mothers and their partners attending a childbirth prepara-tion class
Figure 6. Doulas-in-training attending classes
pare in real life, such as getting into...