Eye Tracking, Immersion, and UI Design
A great deal of the User Interface design for Digital Games and Apps is just copied from other successful titles, or from what appeals to the developer, and I guess I am no different. Having taught Game Design for many years, I have preferences of what I believe to work for the player and what I presume does not. However, much of my way of thinking is based on research.
It is well over a decade ago now, but I was fortunate enough to be able to play with an early design Eye-Tracking device. I was endeavouring to learn what differences there were in game genres and what factors may contribute to player immersion. While player immersion is critical in a serious game for the increased uptake of knowledge, it is also paramount in the commercial world in what we call player retention. We want our players to keep coming back, and this is fostered by enjoyment from the dopamine the brain releases, which is actually increased through immersion.
As to not bored you with our entire academic study, I will cover the highlights and what they mean for you as a game developer or designer, or even as an academic choosing a good game to teach with. While it can be argued that the screen design or the game genre will dictate the player's eye movement, less eye movement increases immersion, and immersion improves learning and enjoyment (that dopamine thing again). All of this is backed up with research data, but we were looking at commercial games for entertainment and not for the purpose of learning. We recorded the following results for the tested game genres.
First Person Shooters: The players eye were focused primarily in the centre of the screen and were correlated with the movement of the mouse, as the mouse moves the viewport. Peripheral vision was used for keeping track of health statistics, etc.
Third Person Adventures: Hand-Eye co-ordinations of the mouse resulted in the mouse following closely behind the eye movement. Similar to FPS games, third person games also had the players gaze primarily in the centre of the screen or where the character was located.
2D Puzzle Games: Eye-movement was more rapid and traversed the entire field of play while the mouse remains mostly static. When the mouse is required to move an object, it is done only with peripheral vision.
2D Side-Scrolling Platformers: For most of the tested games, eyes are focused in the centre of the screen and disperse outwards when needed. Some of the more successful platformers employed FPS immersion by limiting the character movement, and used peripheral vision to complete tasks as in a puzzle game.
A game designer can learn from this by restricting the required eye movement as much as possible. Essential information, like you will die soon, should be provided close to the field of play, and non-essential data like health and mana statistics, put them in the peripheral vision as not to be a distraction. Now, some of you may think that all this is obvious, but you would be surprised how many big budget games have bad screen design, resulting in zero immersion, and this can kill a title before it is even released. So you should give a minute or two to correlate your screen design with the game genre, and where you think the player will mostly be looking.
The last gem I will leave you with was an addendum we did to our eye-tracking study. We were curious as to what was the difference in eye movement between and expert player and a novice, and just for something different, we used the popular arcade game Dance Dance Revolution. This game is where arrows rapidly advance from the bottom to the top of the screen, and the player must step on the corresponding arrows on the floor panel using their feet.
We found that novice players stared at the top of the screen as the arrows arrived and attempted to place their feet accordingly as quickly as the good. Most did not succeed. We then tested several expert players who were amazing to watch, their feet were moving extremely rapidly, hitting up to 7 arrows per second (I kid you not), and not missing a single arrow throughout the entire song. How did they do it? They looked at the bottom of the screen, used mental pattern matching to see combinations of arrows, and used their peripheral vision to see when the arrows arrived at the top, and when they needed to execute the pattern.
In summary, if you think Game Design is not Rocket Science, well sometime it is. Unfortunately most of the Academics who do this type of research do not talk to the Game Industry, and if they did, the Game Developers rarely listen to them anyway. But I have been an Academic for many years and have been in the Development Industry for longer than I will say. So you my friends, have the benefit of reading my blogs.