ARRR! Augmented Reality Pirates!

Cambridge-based Augmented Reality specialists Optricks Media have just released their newest creation: AR! Pirates.

[box type=”note”]Attention, mateys! As of May 26th, AR! Pirates is available for free on the iPhone, iPod Touch and iPad on the App Store. ARRR!![/box]

It’s a swashbuckling shoot-em-up game for Symbian devices (Nokia, Samsung, Sony Ericsson) that uses a really unique marker-based mechanic: the coins in your pocket!

In AR mode, three coins laid out in a triangle become a desert island, and the surface they are on become the ocean. The idea is to stop waves of marauding pirates from stealing your buried treasure, so you must aim your device to blast the approaching galleons with your cannon, whilst avoiding their fire by moving (yes, moving!) out of harm’s way.

The more ships you sink, the more treasure you earn and the more power-ups you unlock. There are 30 levels in all, including battles with the Spanish Armada, drunken pirates and ghost ships. It costs 99p to download the full version, chargeable to your phone bill.

Here’s a video of the game in action!

As you’ve seen, the innovative approach that Optricks have taken with their markers mean it’s possible to play at any scale. You could use coins to keep the game small enough to play in the pub, or you could ‘upscale’ and use larger discs (like frisbees) to play with massive pirate ships. The best bit: the larger the markers, the larger the field of play, and the more immersive the player experience!

This is one of the best, most purposeful uses of AR that I’ve seen. There are too many use-cases where ‘the medium is the message’ – but in this instance the medium is what connects you to the content, rather than defines your experience of it. Great work Ian, Gavin, Marcus and Dylan.

Here’s the link again: AR! Pirates.

On the Potential for Branded Robots

Last year I wrote about these awesome fighting robots from Japan, where  I asked this question:

“I am very interested in at least progressing research into the potential for branded robotics, androids & cybernetics if any readers have thoughts?”

I received an equally awesome response from one Pius Agius, who challenged me on my Western predilection to see robots fighting rather than fulfilling a higher place in society. I reproduce the key lines of our dialogue here:

“Because [the Japanese] accept robots as part of their daily lives more than a majority of those living in the west does not mean we in the so called west cannot build great machines […] We can make better use of our creations than place them in roman like battles. What does that say about us as a civilization?? Let us build machines that can develop and reach their full potential.”

Stunned to have stimulated such a well-considered response, in answer I cited a company that I think are making some great stuff in this field – Festo:

“I think their design-led approach is not only creating some very useful mechanisms, but can potentially change the way we in the West perceive robotics as part of everyday life.”

Check them out if you like – Festo do great stuff.

Meanwhile, I went to see what I could find out about the guy who’d crashed in with his well-considered comment. I found Pius dwelling on the vibrant community pages of Grandroids, a Ning-based social network full of heavyweight discussion on robotics. Members spoke of a ‘Steve Grand’ as the patriarch of their micro-culture. I’m coming back to this…

I don’t think I’ve mentioned this before, but I grew up surrounded by members of the Games Industry in Cambridge. My father was Director of Development at Millennium Interactive, which became Cyberlife, then Creature Labs, and then Gameware Development.

The common thread between these companies was a breakthrough series of Artificial Life games called Creatures. Cyberlife was created to commercialise the work of this very same Steve Grand, where together with a team of artists and programmers they went about developing the Creatures series.

Though artificial life simulators are now a well-established genre (Tamagotchi; Sims; EyePet), the series was first to reach critical and commercial acclaim. Players would take on the role of keepers to cutesy ‘Norns’. But these were no ordinary creations, and in the 90’s Creatures was far ahead of its time.

These creatures would learn and grow, each with their own neural network, and were motivated to survive, and eventually breed in order to pass on their digital genotype. They had the ability to adapt and evolve, iterating towards an understanding of and harmony with their environment.

Years later, Steve is well-established as the leading thinker in AI and robotics. As well as mounds of academic submissions, he’d been running a project to build a series of intelligent robots for rent, as crowd pullers in public events and trade shows. His first robot was a five foot tall humanoid female called Grace, I discovered.

Because I’d found myself on his site, and because I know the guy, I thought I’d go to Steve to ask my initial question once more:

Hello Steve,
This is Tom Saunter here, Ian’s son.

A member of this very network recently commented on my blog, and one Google later I found myself here. With such a vibrant community there’s so much to digest, so I thought I’d go straight to the source…

Part of my job these days is to seek out emerging technologies for advertising purposes, and now that I’ve read about your Grandroids project I am interested to hear your thoughts on how you feel robotics could be of benefit to brands and, in turn, to consumers.

Besides increased traffic to conference booths, what part do you feel your robots might reasonably play when faced with a brief to change the buying behaviours of the general public?

There’s got to be a great piece of research in there.
Do you know anyone who can help me with an answer?

All the best,
Tom

The response, and get ready for it, was this phenomenal piece of prose:

[…] So, um, how might robots like Grace change buying behaviours? God knows! They could certainly have an impact on brand perception, and I suspect that’s a double-edged sword. If the robot is suitably impressive then it improves the company’s image, but if it’s a bit naff then at best it’s just a novelty to draw crowds that the client would then have to secure by other means, and at worst it damages the client’s image.

For instance Asimo has done wonders for Honda’s public image (not in terms of AI, particularly, just general technology), but some other Japanese robots have fared less well, especially those that fall into the Valley of the Uncanny. In other words, they’re lifelike enough to trigger the circuits in our brains that detect things that “aren’t quite right” in other people (signs that we’re being deceived or threatened, say), but they’re not lifelike enough to actually pass the test, so we find them disconcerting. 3D computer games frequently suffer from the same problem, as I’m sure you know, and years ago I predicted that as 3D graphics got better, the demands on intelligent behaviour for game characters would grow intense.

Anyway, I’ve gone off on a tangent. It was a big factor in our design for Grace, though. We deliberately made her look like a robot and didn’t give her human-like skin, etc. Instead I relied on psychological cues of sexiness and lifelikeness that didn’t risk us falling into the Valley of the Uncanny. My point is, you have to get the psychology right or you won’t produce the positive associations in people’s minds that your client needs. The consumers aren’t necessarily going to be able to articulate these things, so they’ll feel bad without knowing why, and you could damage the brand rather than enhance it. I felt I had enough unique experience in designing artificial lifeforms to stay on the safe side of that boundary, though.

One of the things I was keen to achieve was understatement. There are various companies renting out “robots” as crowd pullers (although really they’re just animatronics or remote controlled) and they go for a big noisy splash – flashing lights, big press releases, comedy routines, etc. I wanted Grace to just sit there at the entrance to a booth and be as much like a normal sales girl as possible. I wanted people to do a double-take and then be intrigued. Let them discover it for themselves. It’s a bit like knowing you’ve just been passed by a really powerful motorcycle because you didn’t hear it coming. I think if you do something like this with a fanfare then people will be primed to find something wrong with it, but if you go for the soft sell then they’ll be supportive and impressed. When I wrote Creatures all those centuries ago, my prime principle was that I shouldn’t try to fool people into thinking norns were alive – I should really try my best to make them alive. If people knew I was being honest and doing my best then they’d be on my side, and I think the same is true here. Undersell the robot and you make their company look good by association, as if there’s a lot more under the hood of their products than they’re letting on.

There are also many other kinds of subliminal association that can work for you or against you depending on the client and your ability to tap into the right psychological triggers. I based the look of Grace on the robots Chris Cunningham designed for the video to go with Bjork’s “All is full of love”, because I think he got a lot of those triggers just right – especially the tension between femininity and technology. It’s a bit like designing the iPod – the right curves and the bits you leave out are so important. And with real robots you have to get the behaviour right too, which is a big subject all by itself. Almost all current robots fail miserably in that regard, especially by being too predictable and not subtle enough.

But I don’t think I’m really answering your question, am I? Sorry. Advertising and marketing aren’t my field (I have quite enough fields without adding any more). I don’t really know of anyone who knows about this stuff. One of our “competitors” in New York has a site where they talk quite a bit about the marketing potential of their remote-controlled “robots”, but I can’t for the life of me remember the name of the company (so maybe their advice doesn’t work!).

Looks like it’s down to you to figure it out…

There it is then. The planet’s preeminent ALife & robotics academic, whom has been referred to by Richard Dawkins as “the creator of what I think is the nearest approach to artificial life so far”, is leaving it up to us to answer the big questions:

  • What is the potential for branded robots?
  • Will they ever form part of a marketing strategy?
  • Will we ever allow robots a part in everyday life?

And so, I ask again, dear reader, what do you think?

Let me know in the comments.

Summary So Far

In summary, Mobile AR has many paths leading to it. It is this convergence of various paths that makes a true historical appraisal of this technology difficult to achieve. However, I have highlighted facets of its contributing technologies that assist in the developing picture of the implications that Mobile AR has in store. A hybridisation of a number of different technologies, Mobile AR embodies the most gainful properties of its three core technologies: This analyst sees Mobile AR as a logical progression from VR, but recognises its ideological rather than technological founding. The hardware basis of Mobile AR stems from current mobile telephony trends that exploit the growing capabilities of Smartphone devices. The VR philosophy and the mobile technology are fused through the Internet, the means for enabling context-based, live-updating content, and housing databases of developer-built and user-generated digital objects and elements, whilst connecting users across the world.

I have shown that where the interest in VR technologies dwindled due to its limited real-world applicability, Mobile Internet also lacks in comparison to Mobile AR and its massive scope for intuitive, immersive and realistic interpretations of digital information. Wearable AR computing shares VR’s weaknesses, despite keeping the user firmly grounded in physical reality. Mobile AR offers a solution that places the power of these complex systems into a mobile telephone: the ubiquitous technology of our generation. This new platform solves several problems at once, most importantly for AR developers and interested Blue-chip parties, market readiness. Developing for Mobile AR is simply the commercially sensible thing to do, since the related industries are already making the changes required for its mass-distribution.

Like most nascent technologies, AR’s success depends on its commercial viability and financial investment, thus most sensible commercial developers of AR technologies are working on projects for the entertainment and advertising industries, where their efforts can be rewarded quickly. These small-scale projects are often simple in concept, easily grasped and thus not easily forgotten. I claim here that the first Mobile AR releases will generate early interest in the technology and entertainment markets, with the effect that press reportage and word-of-mouth behaviour assist Mobile AR’s uptake. I must be careful with my claims here however, since there is no empirical evidence to suggest that this will occur for Mobile AR. Looking at the emergence of previous technologies, however, the Internet and mobile telephony grew rapidly and to massive commercial success thanks to some strong business models and advancements in their own supporting technologies. It is strongly hoped by developers like Gameware and T-Immersion that Mobile AR can enjoy this same rapid lift-off. Both technologies gained prominence once visible in the markets thanks to a market segment called early adopters. This important group gathers their information from specialist magazine sources and word of mouth. Mobile AR developers would do well to recognise the power of this group, perhaps by offering shareware versions of their AR software that encourage a form of viral transmission that exploit text messaging.

Gameware have an interesting technique for the dissemination of their HARVEE software. They share a business interest with a Bluetooth technology firm, which has donated a prototype product the Bluetooth Push Box, which scans for local mobile devices and automatically sends files to users in acceptance. Gameware’s Push Box sends their latest demo to all visitors to their Cambridge office. This same technology could be placed in public places or commercial spaces to offer localised AR advertising, interactive tourist information, or 3D restaurant menus, perhaps.

Gameware, through its Nokia projects and HARVEE development program is well placed to gain exposure on the back of a market which is set to explode as mobile offerings become commercially viable, ‘social’, powerful, multipurpose and newsworthy. Projects like HARVEE are especially interesting in terms of their wide applicability and mass-market appeal. It is its potential as a revolutionary new medium that inspires this very series.

Gameware: A Case-Study in AR Development

I have been aided in this series by a connection with Gameware Development Limited, a Cambridge-based commercial enterprise working in the entertainment industry. Gameware was formed in May 2003 from Creature Labs Ltd, developing for the PC games market which produced the market leading game in Artificial Intelligence (AI), Creatures. When Gameware was formed, a strategic decision was made to move away from retail products and into the provision of technical services. They now work within the Broadcasting and Mobile Telephony space in addition to the traditional PC market. I use this business as a platform to launch into a discussion of the developments current and past that could see AR become a part of contemporary life, and just why AR is such a promising technology.

Gameware’s first explorations into AR came when they were commissioned by the BBC to develop an AR engine and software toolkit for a television show to be aired on the CBBC channel. The toolkit lets children build virtual creatures or zooks at home on their PCs which are uploaded back to the BBC and assessed:

 

A typical Zook, screenshot taken from Gameware's Zook Kit which lets children build virtual creatures
A typical Zook, screenshot taken from Gameware's Zook Kit which lets children build virtual creatures

 

The children with the best designs are then invited to the BAMZOOKi studio to have their virtual creatures compete against each other in a purpose-built arena comprised of real and digital elements. The zooks themselves are not real, of course, but the children can see silhouettes of digital action projected onto the arena in front of them. Each camera has an auxiliary camera pointed at AR markers on the studio ceiling, meaning each camera’s exact location in relation to the simulated events can be processed in real time. The digital creatures are stitched into the footage, and are then navigable and zoomable as if they were real studio elements. No post-production is necessary. BAMZOOKi is currently in its fourth series, with repeats aired daily:

 

BAMZOOKi, BBC's AR game show where children’s zooks compete in a studio environment
BAMZOOKi, BBC's AR game show where children’s zooks compete in a studio environment

 

BAMZOOKi has earned Childrens BBC some of its highest viewing figures (up to 1.2 million for the Monday shows on BBC1 and around 100,000 for each of the 20 episodes shown on digital Children’s BBC), which represents a massive milestone for AR and its emergence as a mainstream media technology. The evidence shows that there is a willing audience already receptive to contemporary AR applications. Further to the viewing figures the commercial arm of the BBC, BBC Worldwide, is in talks to distribute the BAMZOOKi format across the world, with its AR engine as its biggest USP. Gameware hold the rights required to further develop their BAMZOOKi intellectual property (IP), and are currently working on a stripped down version of their complex AR engine for the mobile telephony market.

I argue, however, that Broadcast AR is not the central application of AR technologies, merely an enabler for its wider applicability in other, more potent forms of media. Mobile AR offers a new channel of distribution for a variety of media forms, and it is its flexibility as a platform that could see it become a mainstream medium. Its successful deployment and reception is reliant on a number of cooperating factors; the innovation of its developers and the quality of the actual product being just part of the overall success the imminent release.

As well as their AR research, Gameware creates innovative digital games based on their Creatures AI engine. They recently produced Creebies; a digital game for Nokia Corp. Creebies is one of the first 3D games which incorporates AI for mobile phones. Gameware’s relationship with Nokia was strengthened when Nokia named them Pro-Developers. This is a title that grants Gameware a certain advantage: access to prototype mobile devices, hardware specifications, programming tools and their own Symbian operating system (Symbian OS) for mobile platforms. It was this development in combination with their experiences with BAMZOOKi and a long-standing collaboration with Cambridge University which has led to the idea for their HARVEE project. HARVEE stands for Handheld Augmented Reality Virtual Entertainment Engine.

Their product allows full 3D virtual objects to co-exist with real objects in physical space, viewed through the AR Device, which are animated, interactive and navigable, meaning the software can make changes to the objects as required, providing much space for interesting digital content. The applications of such a tool range from simple toy products; advertising outlets; tourist information or multiplayer game applications; to complex visualisations of weather movements; collaborating on engineering or architectural problems; or even implementing massive city-wide databases of knowledge where users might ‘tag’ buildings with their own graphical labels that might be useful to other AR users. There is rich potential here.

In HARVEE, Gameware attempt to surmount the limitations of current AR hardware in order to deliver the latest in interactive reality imaging to a new and potentially huge user base. Indeed, Nokia’s own market research suggests that AR-capable Smartphones will be owned by 25% of all consumers by 2009 (Nokia Research Centre Cambridge, non-public document). Mobile AR of the type HARVEE hopes to achieve represents not only a significant technical challenge, but also a potentially revolutionary step in mobile telephony technologies and the entertainment industry.

Gameware’s HARVEE project is essentially the creation of an SDK (Software Development Kit) which will allow developers to create content deliverable via their own Mobile AR applications. The SDK is written with the developer in mind, and does the difficult work of augmenting images and information related to the content. This simple yet flexible approach opens up a space for various types of AR content created at low cost for developers and end-users. I see Mobile AR’s visibility on the open market the only impediment to its success, and I believe that its simplicity of concept could see it become a participatory mass-medium of user-generated and mainstream commercial content.

Yamake


Yamake Shortfilm from Yamake on Vimeo.

Tonight I’m going to a press event for the launch of Yamake, the first user-generated social game for Mobile.

Created by Gameware Development (Cambridge), and published through N-Gage by Nokia, the game allows users to share content with others based on a simple gaming mechanic.

A full review will appear once I’ve got a copy, but in the meantime check out this promo video.

Addictive Interactions

Can Digital Games Create A Dependency?

Late in 2001, 21 year old Shawn Woolley shot himself to death in his apartment. He was an EverQuest addict, clocking up to twelve hours a day inside the game’s expansive online world. Shawn had epilepsy, and would often have seizures directly linked to the time spent staring at his brightly-lit computer screen, yet he would continue to play. He quit his job and he would ignore his family just to advance his character in the never-ending game.

An article in the Milwaukee Journal Sentinel reported that “A psychologist diagnosed [Shawn] with depression and schizoid personality disorder, symptoms of which include a lack of desire for social relationships, little or no sex drive and a limited range of emotions in social settings.” However, these problems matter very little in a virtual world, a fact that inevitably caused Shawn to take shelter within its walls. He created a character that allowed him respite, causing his psychological issues to disintegrate each time he entered this ultimate escapist universe.

Shawn’s mother is now attempting to sue the game’s developers, claiming that Sony is directly responsible for his clinical addiction and eventual suicide. It is unknown as to the true reasons Shawn took his own life, however his mother suspects that a within-game event caused his breakdown:

“Elizabeth Woolley remembers when her son was betrayed by an EverQuest associate he had been adventuring with for six months. Shawn’s online brother-in-arms stole all the money from his character and refused to give it back. “He was so upset, he was in tears,” she said. “He was so depressed, and I was trying to say, ‘Shawn, it’s only a game.’ I said he couldn’t trust those people””

(Milwaukee Journal Sentinel Online, March 31st 2002)

But of course for Shawn it wasn’t only a game, it was his raison d’être. He devoted his life to play, and was in a state of immersion as deep as anyone might ever hope to achieve. Shawn was not the only one to have experienced such dependency on the online game, in fact EverQuest is referred to by certain of it’s 450,000 plus users as NeverRest or EverCrack, in reference to it’s perhaps inherently addictive qualities.

So how can a game be addictive? Digital gaming cannot be physiologically addictive in the way that opiates, caffeine or nicotine can be, because there is not a direct physical link to the gamer’s neurology. Although physical dependency to gaming cannot by its nature occur, games cannot claim to be entirely safe either:

“Psychological addictions are a dependency of the mind, and lead to psychological withdrawal symptoms. Addictions can theoretically form for any rewarding behaviour, or as a habitual means to avoid undesired activity, but typically they only do so to a clinical level in individuals who have emotional, social, or psychological dysfunctions, taking the place of normal positive stimuli not otherwise attained.”

(‘Addiction’, Wikipedia, 10 December 2005)

It is highly likely, then, that Shawn was indeed psychologically dependent on the game. But is his mother right to prosecute, given Shawn’s neurological issues? It is important to remember that although it is never the intention of a game developer to create an addicting piece of software, there is certainly the need to create a game that rewards repeat plays. This ensures that the game will be a commercial success. In the case of monthly subscription games like EverQuest it is commercially sensible that gamers remain interested for several months and pay as such. There is a great emphasis on hooking new players and keeping current players captivated. This is done by adding new and exciting content, allowing for alliances and clans to develop, and to design a never-ending game. Gamers can of course choose to exit play, but why should they when the game experience promises to get even better? A game’s success is based on how fun it is to play, not how addicting it is. The two are simply quite hard to distinguish.

There is a fundamental difference between gamers that are addicts and gamers that are just highly engaged.

The immense majority of gamers will not develop psychological addiction to digital play, but are certainly likely to experience a milder form of compulsion that keeps them playing. This is not because games are addictive, but because games can be incredibly fun. It is very hard, then, to distinguish between those that are highly engaged with a game: that is to say they are immersed; in the flow; and experiencing a reward-based benefit from continued play, and those that are psychologically addicted to a game: that is to say they are not just immersed but entrenched, not just in the flow but fully empathetic to their avatar; and whose greatest benefit of play is the gratification of their psychological dependency for yet more play.

So what happened to Shawn to get him in this state? Of course his schizophrenia played a large part in blurring the boundaries between his reality and his virtual world, but is that to say the casual gamer might never become so dangerously immersed? Could the magic circle ever wholly absorb a person? DeKoven (2002, p. 33) gives an account of Huizinga’s (1970) magic circle:

“[A] device to which we have access in order to keep the game going is the boundary that separates the game from everything else around it. Because there are boundaries, there are ways to get out of the game when you have to. Play is a voluntary act. You can’t play if you aren’t willing to. You can’t play if you feel you are obliged to. No game or toy can guarantee that it can make people play. You gotta be in the mood.”

Of course, for those that are addicted to gameplay, they are always in the mood. But then they aren’t really playing in the Huizinga sense. Gameplay must be voluntary, so for those that are playing purely to satisfy a compulsion are not really playing. Try telling that to the legions of EverCrack junkies. What are they really doing, if not playing? Salen and Zimmerman (2004, page 452) offer an account of Bolter and Grusin’s (1999) remediation theory that may help us understand the true mind state of the immersed player:

“Media operate according to a double logic. On one hand, media participate in… immediacy, the ability to authentically reproduce the world and create an alternative reality. At the same time, media also remind their audiences that they are constructed and artificial, a characteristic that Bolter and Grusin call hypermediacy… All media combine these two processes into what they term remediation, an experience of media in which immediacy and hypermediacy co-exist”

So the immersed player experiences the game in a state of remediation: aware that they are playing, yet suitably attached to a game not to disrupt the magic circle. These EverCrack junkies know they are playing, because they experience hypermediacy. An addicted player might experience a game purely as immediacy, where his life within the game unfolds as his reality. If this were true, then a game can never be accused of forcing an addiction, rather the onus is on the player to continually perceive gameplay in remediation. Players like Shawn that have trouble distinguishing truth from fiction are therefore more prone to psychological addiction. It can be suggested that the boundaries between reality and the game world suddenly dissolve when both the gamer’s propensity for addiction and the amount of gratification meet midway. That is not to say developers should hold back on making their games less rewarding, or better than reality, but perhaps that games should have better warnings for those who are less conscious of themselves as players.

Game ‘addiction’ is a relatively new thing. Before the invention of the home computer, and later the console, there really wasn’t much to be done on one’s own. Before interactivity there was just ‘activity’: reading; watching television or films; one-way communication with an entertainment medium. Then came the technology that changed ‘alone-time’ forever, in the process giving those anti-social types an excuse not to go outside and play with the other boys. The hardcore gamer was born, and with them new worries of digital addiction and stories of mind-numbing, brain-washing and the dumbing-down of the youth generation. Hardcore players are more likely to report their full engagement with a game, sometimes to the point of their realities shifting and their emotional drives realigning to the needs of their virtual representatives within a game.

What we see in the behaviours of hardcore gamers is not addiction, but engagement. Digital games are not addictive, although players may show characteristics of a dependency on them. Games are built around one core concept: ‘What would be fun for the player?’ As games get better and more realistic, it becomes easier to forget that we are really playing at all. The magic circle must be reinforced if it stands a chance of surviving intact against the next generation of ultra-immersive games. Gamers can only be protected from psychological addiction to these games if the notion that they are ‘just playing’ is constantly reinforced. A player’s double-consciousness should actually make play more fun, because the magic circle can remain unbroken. Developers would do well to remember that games are supposed to be fun, and the easier they make it to retain a lusory attitude, the more people will realise games are a safe medium after all. Developers are dependent on a good reception, and if they play things right, there won’t be any more blood on the keyboard.

1593 words

Bibliography

Bolter, Jay David and Grusin, Richard (1999). Remediation: Understanding New Media. Cambridge, MA: MIT Press.

DeKoven, Bernie (2002). The Well-Played Game: A Playful Path to Wholeness. 3rd edn. Lincoln, NE: Writers Club. Retrieved 11th November 2005 from http://www.deepfun.com/WPG.pdf

Huizinga, Johan (1970). Homo Ludens: A Study of the Play Element in Culture. London: Temple Smith

Milwaukee Journal Sentinel Online (March 31st 2002). “Death of a Game Addict” Retrieved 13/12/05 from http://www.jsonline.com/news

Salen, Katie and Zimmerman, Eric (2004). Rules of Play: Game Design Fundamentals. Cambridge, MA: MIT

Wikipedia (December 10th 2005) “Addiction” Retrieved 13/12/05, from http://en.wikipedia.org/wiki/Addiction

Further Reading
Poole, Steven (2000). Trigger Happy: Videogames and the Entertainment Revolution. New York: Arcade

Sutton-Smith, Brian (2001). The Ambiguity of Play. Boston: Harvard University Press