Cognitive Walkthrough for the Microsoft Xbox 360 ® Gamepad Controller

The gamepad is a device with a direction controller situated on its left side and action buttons on the right. Even if, along the years it changed its shape, size and gained a few extra buttons and options, the device retains its basic form and button placement. These devices are the primary means of input for video games consoles. Gamepad Controllers allows enhancing the perception of elements residing in a non-spatial part of the gaming design space, and makes up for the broken perceptual link that occurs when a player is linked to a virtual avatar through a display and an audio system.

Among contemporary objects, Gamepads are peculiar given their existence both as physical artifacts and as interfaces to control characters in digital environments. Unlike joysticks, they correspond to a type of game controller held in the hand where fingers interact with buttons, sliders and tiny sticks. Therefore, observing this unique device enables to highlight critical implications about human-computer interaction and innovation in the field of new media: the complex relationship between controllers and video game design, the evolution of game interfaces as well as the evolution of technical objects in general.

Figure 1

The most current controller generation for the famous Xbox 360 ® is not the exception. This sophisticated controller represents an interesting evolution from the previous versions of gamepads. A lot of functions has been added: Instead of two fire buttons, the controller now has four, it retained its digital directional pad but now has two extra analog sticks, four extra buttons on the front side (Left 1 and 2 and Right 1 and 2), a guide button, charge port, ring of light, audio port, battery bay, back and start button, a vibration function and even wireless technology, as appreciated in Figure 1. It is important to know, that Microsoft target audiences for this device are male, hard core gamers from +17 years old.

Sticks and directional pad interactions correspond to spatial movement and/or directionality; buttons correspond to actions the user can take. They tend to be fairly simple; limiting the user’s actions to a few well understood options (though complexity can increase with the number of buttons and context-sensitive buttons). They are efficient, as the user can rapidly and repetitively enter game commands with the same muscle movements. Such interfaces have proven to be familiar and comfortable after having been the standard for so long.

Figure 2

The Controller provides a good conceptual model of its use. The quality of the materials used in the controller, from the enclosure to the different buttons and sticks, are first rate and provides a solid feeling. The curvature given to the top surface plays an important role on the way the face button feels, how everything on the controller’s surface seems handy and easy to reach and at the same time creates a constrain about how the controller should be manipulated. The user can easily interpret that the controller must be grabbed with both hands. Once the controller is grabbed, the natural position of the thumbs will correspond almost exactly with the actual location of the Sticks and Control Buttons. Ergonomics for the triggers buttons perfectly accommodates the index and middle fingers; giving the user the sense of the device as a natural extension, as appreciated on Figure 2. The controller is very comfortable, light and the layout is quite well done. It can be used while standing, it is easy to learn and the presence of two analog stick, several buttons offer a great variety of input possibilities. As of now, though, the majority of virtual environments using the Xbox 360 ® Gamepad as an interaction device allows users to navigate freely, look around and offers a very good degree of interactivity.

In regards to the possible actions that the Xbox 360 ® controller provides and suggest to the user, we can find a quiet good set of affordances: spatial movement, fast triggering, double triggering, multiaction points, up to 6 simultaneous command combinations, among many others.

In terms of usability, regular gamers tend to adapt naturally to this new version of Controller. When the controls are too difficult to learn or use or if they detract from the gaming experience, users will decide not to play the game (Smith, 2006). This effect is sometimes seen in new players or casual users when they have to fight the controls more than the game mechanic and gives up in frustration. However, this symptom is not exclusive for the Xbox 360 ® Controller, but for all video games controllers or interfaces known so far.

A factor that is easily conveyed by users first iteration in modern video games, is the loss of sense of direction that occurs when a player navigates a virtual space with his/hers real-world navigation skills, while being perceptually linked to this world through a display, audio system and a haptic controller interface. The Xbox 360 ® overcomes this phenomenon by allocating the gamepad controller functions according to the human reality standard references. For example, when people play a game, the game pad faces to the ceiling. Hence, it is reasonable to use and easy to deduce that the “up” and “down” keys of the “Cross pad” allows performing inward and outward movements.

Control components are visible and are layout in a way that it is clear to user what actions are possible and what the appropriate way to perform those actions is: move, press, push down, pressure, etc. The Xbox 360 ® Controller provides means of easy identification of interaction elements, so the user is able to perform intuitively. In the other hand, the controller layout provides overall flow needed to accomplish end goal, therefore golfs of execution are easy to map. In terms of gulfs of evaluation, this will be addressed when evaluating the feedback channels provided by the controller. These characteristics go in hand with the Principle of “Knowledge in the World”. This concept refers to information that exists in the world that we don’t need to memorize to utilize. This is evident by the fact that game players do not memorize the button combination. They play intuitively without thinking, watching or calculating their actions over the controller. 

Figure 3

Another interesting characteristic is the presence of signifiers. A signifier, as defined by Norman, is some sort of indicator or signal in the physical or social world that can be interpreted meaningfully (Norman, 2008). These are present in the Xbox Controller via four independent quadrants that lights up according to what controller number must be pressed or hold, as shown in Figure 3. Allowing the user to easily interpret what button and in which direction to press in order to complete the option explained on the screen.

In relation to the feedback mechanisms, the Xbox 360 ® Controller allows for novel way to provide the user with information hard to convey in a subtle visual manner. The Xbox 360 ® controller has two vibration motors that enable it to give haptic feedback in stereo by varying the output of the different motors. For example: the controller vibrates when the player fires his or hers weapon, or when the player is being hit by enemy fire, when the player is near from the edge of a building, falling from high altitude, etc. According the ISO 9241-9 standard about ergonomics requirements for non-keyboard input devices, the Xbox 360 ® Controller complies with the usability aspects shown in Table 1. In other hand, regarding targeting tasks that involves on screen point selection, again the layout and shape of the interaction points allows for an easy mental mapping. Targeting is a common task in video games, and the action can be interpreted in a variety of ways, ranging from shooting on-screen enemies to selecting on-screen menu options.

Usability Aspect	Rating
Force required for actuation	Low
Smoothness during operation	Smooth
Mental effort required for operation	Moderate
Accurate pointing	Moderate
Operation speed	Very Fast
Finger fatigue	Low
Wrist fatigue	None
General Comfort	Confortable

Table 1. Xbox 360 ® ISO 9241-9

The traditional controller scheme locates the analogue stick right below the thumbs, this can interpreted as a forcing function to suggest that one stick could be used for navigation and a second analogue stick for targeting. Normal input generally involves moving/pressing stick or pushing buttons in a certain sequence, or at a certain time, to perform game actions. In regards to the Norman’s 7 Stages of Actions, the Xbox 360 controllers allows for multiple actions and functions. For the purpose of this analysis we will consider a simple interaction with a games setting menu for effects volume control. Having this said, we can determine the following outcome:

Action	Stage	Outcome
Activity	Forming the Goal	The user presses the Menu button. The Volume Settings menu offers an option to lower the effects volume.
Interaction	Forming the Intention	There's a control labeled “Effects”. The user understands that he can use the gamepad controller to manipulate it in some way to reduce the sound effect volume.
	Specifying the Action	“Effects” control looks like a little handle on a horizontal track. The user understands that if he could grab the handle and drag it along the track, the volume will change. The user maps the controller sticks with the available screen functions. The controller stick allows for left/down and right/up movement.
	Executing the Action	The user decides to move the Stick to the left.
Information	Perceiving the State of the World	As the user moves the stick to the left, the handle on the screen moves towards the left. When the user releases the stick the game plays a sample sound effect.
	Interpreting the State of the World	Now the handle is closer to the icon of the smaller speaker and the sample sound seemed to be quieter than the one that was heard during the game, before moving the handle with the controller stick.
	Evaluating the Outcome	The user wanted to turn down the sound effects volume. He continues playing and notice that the volume of sound effects is lower.

Table 2. Norman 7 Stages of Action Analysis

A typical user would move through these stages subconsciously in a couple of seconds, but if he isn't able to smoothly move through each and every one then it can lead to confusion or frustration. The largest hurdle to involvement is the user interface, or how a player interacts with the game. Analyzing usability and adhering to accessibility design principles makes it both possible and practical to develop fun and engaging game user interfaces that a broader range of the population can play. The success for a normal execution will be an appropriate coordination between the controller and the video interface, which as we know is out of the scope of this analysis. 

Finally, the Xbox 360 ® Controller implements a mixture of interlocking and lockout mechanisms for error control and management. The user is unable to perform forbidden operations like playing the game without calibrating the control, navigating away from the screen, etc. Again the feedback channels via the vibration function and the visual clues on the light ring are used to provide memory aid and guidance in case of wrong usage. Normally this error management functions are reinforced by on screen visual clues.

In conclusion, the Xbox 360 ® Controller is an overall very well designed artifact. Its adoption has been considerable having more than 40 million users, with over 70% rate of 5 points of satisfaction (Amazon Reviews, 2010). It is likely that many of the upcoming innovations in gaming will come from new developments in user interface technology. Direct manipulation of user interfaces, context sensitivity, and cross platform titles will all result in new ways to play. Combining these technologies can lead to a new generation of games and experiences that are fun and exciting for a broad user base. If thoughtfully conceived these technologies can lead to added usability and accessibility for systems as well.

Recommendations

The proximity between both triggers and the respective bumper buttons (See Figure 1). These elements are close in distance and aligned at the same depth; both pairs tend to be confused between each other, resulting in a wrong button press. I would suggest giving special shape to these buttons.

Analogue stick targeting is not a good method for performing point-select tasks. Despite this, the method is used in many games that use traditional controllers (Castellucci, 2008). It would be a good idea for future generations of consoles to introduce new controller schemes which would make targeting and point-selection easier (i.e. Wii mote)

Sometimes it is unclear how long to press a specific button. Indicating the estimated pressing time via visual clue would help to fix this issue.

References

Norman, D. (1990). The Design of Everyday Things. New York, NY. Currency and Doubleday.

Eysenck, M. (2007). Fundamentals of Cognition. New York, NY. Psychology Press.

Norman, D. (2008) . Signifiers, Not Affordances. Interactions Archive. XV. Nov., pp. 42-44.

Smith, J. David. (2006). Use of eye movements for video game control. ACE '06: Proceedings of the 2006 ACM SIGCHI international conference on Advances in computer entertainment technology, 20.

Hill, W., Hollan, J. D., Wroblewski. (1992). Edit Wear and Read Wear: Text and Hypertext. Proceedings of the 1992 ACM Conference on Human Factors in Computing Systems (CHI '92).

Castellucci, S. J. and MacKenzie. (2008). Text entry using three degrees of motion, Extended Abstracts of the ACM Conference on Human Factors in Computing Systems - CHI 2008., 3549-3554.

Silfverberg, M., MacKenzie. (2001). An isometric joystick as a pointing device for hand-held information terminals, Proceedings of Graphics Interface 2001. Information Processing Society, 2001, 119-126.

Amazon Reviews. Customers Review for Xbox 360. Web. October 7, 2010.[Online] http://www.amazon.com/review/product/B000UQAUWW/ref=dp_top_cm_cr_acr_txt?%5Fencoding=UTF8&showViewpoints=1