Human factors at the Navy; “The ones who win…”

I am slowly starting to get integrated into my work at the Navy. I am part of the Naval Undersea Warfare Center’s (NUWC) Combat Systems Division. NUWC is divided into many departments that are divided based on submarine systems. If you think of the submarine as an information processing unit, you have the input in the form of sonar and other sensors, the output of navigation and ordinance, and then you have the “brains” that integrates data and provides output solutions. This is what Combat Systems does.

The motto I see over and over is:

The ones who win get the right amount of the right information to the right people at the right time to help them make the right decision.

From a human factors standpoint, this is a critical mission. Information is needed in a real-time fashion; if a sonar display is 30 seconds old, it could be useless. Additionally, who needs to see what information? Commanding officers does not need the low-level details of how a target was identified. Instead, they need a big picture overview of the battlespace. Similarly, operators do not need the gritty numbers output by the sensors. The data needs to be interpreted for the optimal presentation to the operator. This is the domain of the Data Fusion group, which deals mostly in engineering, algorithms, and mathematics.

My boss put it most succinctly: engineers need to make sure bits flow to the screen. Psychologists need to make sure the information flows into the brain. From the sounds of things, I will help accomplish that task this summer by working with the group’s Applied Science Laboratory eyetracker.

It’s not the one I’m used to, but it’s much better for applied settings versus basic research. I am looking forward to it! More details as I get them.

Vision Sciences 2008

I am at the Vision Sciences Society conference right now in Naples, FL. It’s my fourth VSS, and the presentations are of high quality and the beaches are of the same high standard. I’m presenting two posters at the conference.

The first is a study I’m doing with my labmates and Carl Smith (Evaluating Design) looking at eye movements in experts and novices while they view a movie of the first-person shooter Quake 4 and have to detect targets. The big picture is that more experienced players make fewer eye movements for longer periods of time. This reflects previous research that suggests experts have a larger functional field of view, so they can extract more information from the periphery than novices.

The second poster are a series of studies I worked on with my advisor and another faculty member at George Mason University. We examined the effect of holding similar and dissimilar items in working memory to determine how the capacity of visual working memory changed when you had to remember sets of items from different categories. The interesting result is that remembering 2 objects from 2 separate categories (4 total object) led to higher working memory capacity than 4 objects from a single category, but only if faces were part of the two-category set. This is not due to a general “faces are special” effect, as memory capacity for two or four faces alone was never greater than memory for other object classes.

As I attend other interesting talks and posters, I hope to write about them here. Stay tuned!

User interfaces in Iron Man

First off: possible spoilers ahead!

Iron Man was an excellent movie. However, since this blog is not dedicated the movie reviews, I thought I’d discuss some of the user interface elements involved instead.

This video highlights two UI elements that were well thought-out. There are more I’d like to discuss, but I couldn’t find them. There are two clips: one is of a holographic prototyping interface and the other is the Iron Man suit user interface and flight interface:
Click to download (6.5 MB MP4 video)

Holographic Prototyping and Direct Manipulation on the Cheap:

The first clip ends at around 26 seconds and shows off Tony Stark’s (aka Iron Man) holographic prototype interface. The hologram is a sci-fi cliche, but its usefulness is immediately evident. Direct manuipulation has been discussed before, and this typically requires something physical to manipulate. These physical prototypes are expensive to fabricate, especially if multiple revisions are needed. In the clip, Stark has already built out the specs for this piece of his suit, and he’s able to add and subtract parts and accurately visualize the effects of the modifications without fabricating lots of physical prototypes. The coup de grace is when he is able to stick his arm inside of the hologram and test it out. It’s direct manipulation of a prototype without the expense. Because this kind of manipulation is so natural, very little cognitive effort is needed to use this interface.

Flight Suit Interface and Transfer of Training:

The second clip starts at 27 seconds and demonstrates part of the suit’s user interface and the flight interface as well. The flight interface is very similar to that of a fighter jet, which will make transfer-of-training easy from a fighter jet to an Iron Man suit. This will cut down on the need to train users of the Iron Man suit - if they can fly a fighter jet, they can fly this suit.

Main Suit User Interface Voice Commands:

What was most interesting in the clip was how the general UI was controlled. The heads-up display is directly in front of the user’s face, but the user cannot touch the display. Therefore, direct manipulation is out of the question. The suit does take voice commands, as shown in the video. This is an obvious choice, but it is slow to use. Imagine flying at some insane speed under high stress - do you want to have to yell out a command that takes several seconds to issue, then wait for a reply from the suit? Probably not a good idea. The closest thing to voice interaction in this world is the Microsoft Sync system. This system integrates bluetooth phones and MP3 players into Ford cars and is all voice controlled. When it works, the eyes stay on the road for longer and less attention is required to make a phone call or play music. But when it doesn’t work, the error correction is simply a mess. It takes a huge amount of effort and is bad for driving or flying.

This is a great review of the Sync system (see 1:45 for an example of a Sync error as how the user simply gives up):

Main Suit User Interface and Eyetracking:

Besides voice commands, the other control option is eyetracking. If the eyes are focused on something in the environment, a command can be issued to zoom in, take a picture, etc. Issuing that command, however, would have to be done using a voice command or a button-press. The eyes are needed to focus, so something other than the eyes must issue a command. This is not the ideal situation because it requires coordination of multiple systems - the eyes must remain focused on the target while another body part confirms the command. Overall, though, this is not too much of a problem. It is similar to tracking the cursor on a computer screen and clicking the mouse with your finger. Nonetheless, it is a less elegant solution, especially during flight or in combat and the hands are required for another task.

NASCAR: The necessity of top-notch vision.

So you’re driving down a racetrack at 200 mph. Things are flying past you at phenomenal speed, and you need to make sense of it all. Do you need spectacular vision? Sure. But it’s not just acuity (how good your vision where your visual focus is) that matters. What also matters is how well you can process things in the periphery. From an article about Nascar driver Tony Stewart in the New York Times:

For starters, Stewart has superb eyesight — 20/13 in one eye, 20/15 in the other — but it’s not visual acuity that matters so much as a driver’s ability to process everything that drifts into his periphery while he travels at 200 m.p.h. “A driver has to know what’s unfolding in front of him at a rate of a football field a second,” says Dr. Stephen Olvey, a founding fellow of the F.I.A. Institute for Motor Sport Safety.

When there is so much optic flow (a technical term meaning “stuff passing you as you are in motion”) is occurring, it makes sense that you have to be able to deal with something that suddenly appears in your peripheral vision, like another car, debris, or the wall. But not only do you have to detect that event, but you also have to react to it. You need to make a saccadic eye movement to bring the event from the periphery into the fovea - the small portion of central vision where acuity is the best.

A normal person can make a saccade within 250 ms (a rough estimate). That’s one-quarter of a second. 200 mph = 293 feet per second. Therefore, in the time it takes to make a single eye movement, you’ve traveled 73 feet at 200 mph. Add to that the fact that you’re effectively blind during a saccade, and suddenly 73 feet has passed before you know it.

Want to know how good your peripheral vision is? The New York Times article mentioned above has an excellent demonstration to see how good your peripheral vision is and how quickly you can move your eyes And if your performance is not as good as you’d like, you can train like a Nascar champ:

Greg Zipadelli, Stewart’s crew chief, says his driver hones his talent with a popular training tool: PlayStation.

Thanks to John Fedota for the link to the original New York Times article!

Surprise enemies!

In gaming, most levels work by a script: the player passes a certain point, then an enemies pops out of a doorway. However, researchers are using eyetracking technology and our understanding of how eye movements and attention interact to display enemies where they are least likely to be noticed. Even though the eyes are focused in a particular location, attention could be elsewhere. As a great deal of attention capture research has shown, an irrelevant object popping into existence can capture attention and the eyes even if there is no visual focus there.

To learn how to predict where a person’s attention was focused, the pair tested subjects’ reactions to an image suddenly appearing on the computer screen under different circumstances.

The experiments showed two things. First, when someone is looking at a fixed point in a complex part of a scene, they find it harder to divert their attention to a new object. Second, the researchers confirmed previous research suggesting that when looking at a moving object, people tend to focus their attention slightly ahead of it.

Those results were used to design a first-person shoot ‘em up game that could choose to make enemies appear in places where they would be either easy or hard to see. The game tracks a player’s eyes to work out areas they are paying most, and least, attention to.

http://technology.newscientist.com/article.ns?id=dn13264&print=true