Saturday, June 07, 2008

Irrational Sliders

I am reading Predictably Irrational, by Dan Ariely. It's a great read - definitely recommended - describing the consistent irrational biases that frequent human decision making.

The first chapter discusses our tendency to make relative, rather than absolute comparisons. When deciding whether a product is a good value, we will look at the pricing of similar models, rather than the actual relationship between the product and the money spent. (The implication being that a company can make a product seem cheap without changing its price by adding a second, more expensive but similar "decoy" product. Poof! The cheaper product is now a good deal.)

This behavioral tendency explains user reaction to the rendering settings, a subject that makes me irrational on a regular basis. :-)

Time to Change the Settings

The rendering settings will let you select a range of sim detail between some minimum and maximum value. These values are based on the software, not hardware - because we don't actually know how much load any given hardware can support (and with the interaction between settings, finding such a cap is basically impossible). We can only give you a range of choices and let you pick ones that work well.

When a new version of the sim comes out, we sometimes have to recalibrate the settings. If the minimum features the sim can support increase, the minimum setting will be mapped to a new, more expensive behavior. And if the maximum detail the sim can present has increased, the maximum setting will be similarly remapped. We don't have much choice - if we need more "range" on the slider we have to recalibrate it.

I Can't Max Them Out

Here's where human behavior comes in. Humans make decisions based on the relative comparison of easily compared things. Given properties that are harder to measure and easier to measure, we'll pick the easier one. Given a choice of a trip to Rome, a trip to Rome with free breakfast, and a trip to Paris, we'll pick Rome with the free breakfast, opting for the easy to measure relative value. (Is the difference between a trip to Paris and Rome really less than the value of a breakfast? Probably not, but it's a lot harder to evaluate.)

So when we recalibrate the settings, we inevitably here this complaint:

"I used to be able to set the sliders to the maximum setting and now I can't."

Previously I would have said "Why the hell do you care?!?!" -- if the new slider's 50% position looks the same as the old slider's 100% position, why not just set it to 50% and go home happy.

But of course that's not how we think - the immediately comparable is of immediate concern. Ironically we could make the sim less useful but more pleasing by limiting the maximum range of the sliders. Now more users could feel the joy of having everything "set on max" even if the ultimate utility of the sim is reduced.

This One Goes To 11

I'm not sure there's a way around this. The best suggestion I've heard so far is that if we could attach some kind of units to the settings, then at least there would be a quantitative indication that the user isn't losing some perceived value. But I suspect that even this misses the point; it doesn't matter that you're still getting 500 trees per square km - what matters is that you are getting the most you possibly can! (Perhaps this psychology also explains why people like to overclock.)

Austin tried to fight the psychology of "maximum sliders" by naming all of our settings absurd things. Ever wonder why "default" is the lowest object setting, and we almost immediately jump into "extreme", "too many", "insane", etc.? He was trying to fight a losing battle against relative expectations. The natural human behavior is to pick some relative position for calibration, and based on that, every user who has to put objects below the center setting is going to be unhappy about having to use "lower than average" settings. Austin's naming convention may be silly, but it does actually do a little bit to fight this.

Food for thought: how does having multiple levels of reflections change user expectations?


Murmur said...

"(The implication being that a company can make a product seem cheap without changing its price by adding a second, more expensive but similar "decoy" product. Poof! The cheaper product is now a good deal.)"

Every reference to videocard and CPU vendors is purely coincidential :P

Huntsman said...

That's funny, I was thinking "it goes to 11" about two paragraphs before you cited it...!

StormRunner said...

Not being an 'eye candy' kind of guy, I tend to put everything on minimal and go with better flight model analysis. I know, I'm a minority.

I would prefer that you would add a 'basement' setting that will strip the terrain of all objects, textures, etc.

Then another that will adjust plane details from 'realistic gum stuck to the wheels' to '1992 called- they want their graphics back'.

The panel, of course, can't really be adjusted like that if you want to use it. I think you've already got this one covered.

And if you could add a data i/o for how much time was taken by each graphics subsystem, that would help alot for people like me who love to watch numbers all day. No counting of polys, just a time offset.

I don't want much, I know. ;-)

Benjamin Supnik said...


I think the sim can already run in the mode you want...the lowest tex res is pretty close to none. Forward no HUD and forward panel should avoid drawing any plane eye candy. And for lots of numbers, grab "dataRefEditor" and pick the "stats" view...HUGE amounts of'll love it! :-)