Human Pacman:

A Mobile Entertainment System with Ubiquitous Computing and Tangible Interaction

Adrian David Cheok, et al. (2003)

This article describes an extraordinary project done by a group of computer science students at the National University of Singapore. Human Pacman is the name of this project that attempts to create an interactive role-playing game. The idea is to create a totally new gaming experience by using an interface based in tangible computing. In this game the players will be provided with different tools such as virtual reality (VR) and augmented reality (AR) in combination with the physical interactivity among the players and using the real world as their playground.

The players must wear different computerized systems such as head mounted displays (HMD) and a backpack carrying a portable computer,and a GPS receiver, among many other electric sensors. The users can interact with one another physically when they are close enough to each other and via VR or AR when they are further away.

The game consists on the Pacman players having to "eat" special cookies along the way. They also have to find another ingredients such as sugar and flour depending on their previously established goals. The human Pacmans must be careful not to be "devoured" by the human Ghosts that go about the playground. The gameplay takes place with a combination of virtual and real elements. For example, the cookies that the human Pacmans must eat are visible to the user through the HMD as a virtual image. But there also are some physical elements that can be taken by the players. These physical objects carry bluetooth-based sensors so that the system can detect when one of the players have grabbed one of these elements. Both Pacmans and Ghosts have permanent contact with other players that are called "helpers". These players are not walking about the playground, instead they are sitting in a room using a personal computer. The mission of the helpers is to provide information on the exact position of the other players in order to help them plan and coordinate their moves. 

The physical interaction among players is also important. For example, the ghosts can "devour" a Pacman by just taping them on the shoulder. The shoulder of the players have special sensors that detect when they have been touched. 

The project of the human Pacman game is an amazing example of tangible computing where the users can play with their bodies, using their legs for walking about a certain area in the real world and using their hands for taping other users in order to devour them, rather than by only using a keyboard and a computer monitor. And yet this players are indeed interacting with a computer system. At the same time they interact with physical objects in the real world as well as interacting with each other both in a virtual and physical form allowing them to collaborate and coordinate actions in a much more effective way. 

Getting a Grip on Tangible Interaction:

A Framework on Physical Space and Social Interaction

Eva Hornecker and Jacob Huur (2006)

This article explains the huge potential of tangible computing. Unlike the traditional personal computing approach where the main interaction is based on the use of a computer monitor as data output device, and keyboard with a mouse for data input, tangible computing relies on an embodied interaction. This new approach understands the importance of manipulating physical objects as an effective fashion for interacting with a computational system. Tangible computing does not only allow the user for a more natural interaction but it also expands the possibilities for social and collaborative action.  

Tangible user interface (TUI) has had big relevance in the development of human-computer interaction (HCI) in the last decade. For over 30 years have the users been able to just see the digital data through a computer monitor in the same fashion we look through a window. TUI offers the possibility of of interacting with the digital world by manipulating physical objects, being a computer monitor in many cases completely unnecessary. Designing tangible interfaces implies not just designing the digital interface, but also the physical and the interrelation with one another. 

The authors describe four main approaches within TUI:

1.  Tangible manipulation: making a material representation of digital elements in order to control them.
2. Spatial interaction: since the tangible interaction takes place in a three dimensional space then the interaction takes place in form of spatial movement. 
3. Embodied facilitation: it refers to the effects over behavior depending on the configuration of material objects and space.
4. Expressive representation: it focuses on the representation of both physical and digital elements and how understandable are these representations. 

The authors finalize by concluding that each one of these items have different level of importance depending on the application's area where it is being utilized. Regardless which area, the potential of tangible computing is enormous. 

The visual effects of head-mounted display (HMD) and desk-top computer display

Eli Peli (1998)

As computer technology moves forward new ways of presenting the user with visual information are being developed. Technologies like virtual reality (VR) or augmented reality (AR) are requiring new systems being able to show visual information "on the go". But some literature is suggesting that the use of head mounted displays (HMD) has potentially harmful effects on the users' visual system. This article sustains that according to new research there are no major differences regarding the physiological effects in the eyes between using a HMD and a traditional computer monitor.

In this study the author conducted an experiment where a group of adult volunteers play a video game using three visualization modes: HMD in stereoscopic mode, HMD in monoscopic mode and a CRT traditional desktop monitor.

The results suggest that there are clear physiological effects in the users' eyes after having used each one of the three visualization modalities. Even using traditional CRT desktop monitors the users experimented different types of visual anomalies. And the anomalies on the users' eyes after using the HMDs were no greater than those observed after having used CRT displays. These anomalies were basically difficulties in focusing objects at specific distances, blur vison and worsened visual acuity. However, the author emphasizes that all these anomalies disappeared after a certain period of time.

From Consumer Response to Active Consumer:

Measuring the Effectiveness of Interactive Media

David W. Stewart and Paul A. Pavlou (2002)

This article explains the essential differences between traditional media and interactive media, especially regarding advertising and consumer behavior. The authors begin by commenting that for several decades marketing theories had all been based on the paradigm of seeing marketing mainly as a one-way communication between the marketer (the corporations) and the consumers. In other words, in this paradigm the marketer is seen as the only sender of a message. The consumer just reacts to this message with a certain behavior. The interactive media changes this view of communication to a two-ways process where even the consumer send clear and well defined messages to the marketers. Communication, rather than persuasion, is the key concept in the consumer-marketer relationship under the rules of interactive media.

Internet has, without any doubt, represented the main medium that allows interactive communication between the corporations and the end consumers. With this new technology the user can not just select exactly the kind of offers they want to see and even to be able to determine when and how they want to see it, but the viewers can even send constant feedback to the marketers and producers about their wishes and preferences. The possibility of sharing has allowed not only a constant communication between producers and consumers, but consumers can even communicate with one another by sharing products reviews, check the current trends and even being able to form bigger groups in order to be able to negotiate with the companies in more favorable terms.

This expanded communication between all the different actors have had even further consequences in the marketplace. The Internet constitutes a concrete tool for offering products and services with "value added" that will imply a bigger chance for consumers to get higher quality products. However, the authors explain that it is not all that clear whether the Internet has created a real value for which consumers are actually willing to pay. Let's just think of a worldwide service as Facebook. Most people could hardly picture their lives without using this service, and yet it is quite likely that just a tiny little fraction of all that people would actually be willing to pay for using this service, assuming that Facebook was a payed service. Internet and the interactive media have imposed new rules in the marketplace and the companies must therefore rethink their business model in order to be able to detect where the real opportunities for profitability are.  

New Media Interactive Advertising vs. Traditional advertising

A. Bezjian-Avery, Bobby Calder and Dania Cobucci (1998)

The main purpose with this article was to establish the main differences between the traditional "linear" form of advertisement and and the interactive advertisement provided by the so called new media. For this end the researchers conducted an experiment in which they expose a group of volunteers to both forms of advertisement and compare then the results in order to determine the pros and cons of each modality.

The main conclusions they came to was that in many cases traditional linear advertising turned out to be more effective than the interactive ads. This effectiveness was measured based on two main factors:

1. the engagement level: how much time the consumers spend considering and paying attention to the message of the advertising. 
2. the level of persuasiveness: how positive the consumers are about their purchase intentions. 

For doing this experiment the researchers made sure to show the same message (the same message content and the same photos and graphical profile) in both advertising modes (traditional and interactive). They found out that although interactive advertisement get the viewer more engaged and active, in many cases this interactivity implied that the volunteers did not focus much on the message but rather in the interactivity itself. Traditional linear advertising proved to be at least equally effective and in some cases even more effective than interactive ads. 

The authors conclude by saying that more research in this area is needed and that the effectiveness of interactive ads may dramatically improve as people get more used to the narrative form of the new media.  

The Myth of Interactivity or the Interactive Myth?:

Interactive Films as an Imaginary Genre

Kristoffer Gansing (2003)

In this article the author reflects about the real nature of the so called "new media". Interactive media has caused a paradigm shift regarding how we understand spectatorship. In the traditional media we had "passive viewers" while with the new interactive media we have "active users". But what exactly do they mean with interactivity? The author explains that this term has sometimes been used and even misused as a selling argument. The claim that the new media will increase the empowerment of the spectators, liberating them from the passiveness in which they used to be submerged with the traditional media. The problem is that when it comes to interactive films there is no such thing as total interactivity and complete control, because full interactivity will sooner or later pose concrete problems for the storytelling of the film.

The author mentions several video games as examples of experiences where the user has been given many interactive tools in order to control a wide variety of elements, from camera angles during the cinematic presentation to being able to control almost all the actions of the main character. These experiences suggest that developers of interactive media must take into consideration many different aspects in order to make the user to be able to understand the storytelling.

The author concludes by saying that there are two main approaches that can be used:

1. To give the user almost unlimited options for interacting with the game, but this will imply that the video game (or interactive film) will have no definite storytelling.
2. To give the user only a few alternatives to choose from. This will provide a more limited interactivity but it will let the creators of the game or film to offer a much well defined storytelling.

A Touring Machine: Prototyping 3D Mobile Augmented Reality System for Exploring the Urban Environment

S. Feiner, B. MacIntyre, T. Höllerer (1997)

This article written by three students in computer science that developed a device for exploring urban areas through the utilization of augmented reality (AR) for providing the user with extra useful information about the surrounding areas. The device was used in the campus of the Columbia University in New York and it was meant to guide the user with information about the different buildings and departments that exist within that campus. The device consist of three main parts:

1. a head mounted display (HMD) that allowed the user to see the real world through two little monitors, each for each eye. A camera is mounted in front of the right eye-monitor to get the images from the real world. 
2. a backpack carrying a portable computer that runs all the application, a GPS receiver and antenas for receiving and sending the wireless Internet signal from a server in the campus. 
3. a tablet computer with wireless Internet and a stylus for selecting elements on the screen. 

As the user walks around the campus he can see the real world through the HMD that gets the images from the tiny video camera in the right eye. The system knows the exact location of the user thanks to the GPS receiver and in combination with accelerometers and a compas inside the HMD the system senses in which direction the person is looking. The computer then feeds the system with text labels that are superimposed over the images from the real world that the user is seeing. These labels are overlaid exactly (or almost exactly) upon each one of the buildings surrounding the user and they provide him with information that allows him to identify each of those buildings. The tablet computer that the user is carrying is wirelessly connected with the information displayed in the HMD so that he can click on the labels using the stylus in order to get extra information about the selected item. This information is taken from the internet and wirelessly fed into the tablet from one of the many servers in the campus. 

This device was a prototype model and although the results were quite satisfactory, there were several technical issues that must be adressed. The quality of tracking, although it was in many cases sufficiently good, it is clear that for many potential uses of this technology the tracking accuracy must be much higher. New and improved internal sensors such as accelerometers, gyroscopes and magnetic compas will be needed to improve the precision or even the use of other additional technologies yet to be developed such as optic guidance with lasers or other similar technology. The loss of tracking was another frequent problem. In order to get a precise geo-location, a sufficient number of GPS satellites must be visible. The problem is that the signal from these satellites is very weak and it can easily be blocked by surrounding buildings or even foliage. This problem becomes even greater when these AR devices might be required to be used indoors.

The students were, however, very pleased with the results and excited over the many possibilities that this technology could offer in a near future.