About a year ago on a thread on Google Buzz (RIP) I wrote a quick definition of ”positive feedback” and “negative feedback” in terms of their technical, systems design meaning. I figured I would repost it here, since every now and then someone asks me what it is and I search my email to copy/paste it. It’s pretty slapdash but it gets the point across, and people have found it useful. So… here you go, internet.
In short: negative feedback is a system that regulates itself. Think of a thermostat. You set it to a certain temperature T. If the house goes above T, it instructs the systems to cool the house. If the house goes below T, it instructs systems to heat the house.
Positive feedback is where things are reinforced and amplified. Imagine a thermostat that cranks the house hotter when the temperature is above T, and makes it cooler when it’s below T.
The main difference is that in the first example, the temperature will tend to remain at T. In the second example, it is highly unlikely the temperature will be T, and in fact it will trend towards either very hot or very cold.
The simplest example of negative versus positive feedback in game design that I can think of is possession rules in 1-on-1 pickup basketball. A negative feedback rule is something like, “If I score a basket, you get to start with the ball.” By giving an advantage to the loser, you’re evening the playing field a bit and bringing the temperature back down to T, so to speak. A positive feedback rule would be, “Winner keeps the ball.” This means winners tend to keep winning, making the house hotter and hotter.
Randy Smith likes to use Mario Kart as an example of a game with strong negative feedback: items like the Blue Shell cause people in the winning position to be at a disadvantage so those behind can catch up. This is also colloquially known as a “rubber banding” mechanic.
Mainly this is in stark contrast to the other way the terms “positive feedback” and “negative feedback” are used in game design: to signify something positive given to the player (reward) or something negative given to the player (punishment). “Feedback” in general can refer to either feedback loops like I describe, or to the general concept of “giving information to the player about the results of their actions.” I would vastly prefer if we started disambiguating the two usages. I’d like “feedback” to retain the meaning I sketch above, which is probably due to my bias as someone trained as an electrical engineer!
Any suggestions out there for a word other than “feedback” that would describe “giving information to the player about the results of their actions”? Or, hell, a different word for “systems whose outputs determine their future inputs” (which is what I describe in my examples above)?
(Edit: “reinforcement” has been variously suggested here and on Twitter for EITHER kind of feedback. See my comment below on why I think it’s only suitable for the “giving information” kind.)
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