Can't live without it
Have you ever downloaded a file and just below the download link there's a long string of characters called a checksum. That's a number made by (say) applying a technique to the file that generates that unique number. (The SHA-1 checksum for the previous sentence is 5c99e5117276bf29832520b5a8361527990fb744.) And if you want you can run your downloaded file through the same process and generate the number again. If the two checksums down't match then you know that there is an error in the download. This gives you a chance to try again. And it illustrates a central principle of error correction - redundancy of information. In this case the same information is generated twice and compared.
And error correction is extremely important - life and contemporary technology would be impossible without it. Heck even office work is impossible without it.
These days I do a lot of data entry at work. It's useless if not entered accurately. If it's not accurate then you lose a lot of time trying to find the problem. And you have to find the problem because it's a bookkeeping system and if the data is wrong then the books won't balance.
For instance - at the start of one task I count the number of records I need to enter. Then I enter them. If the number of entries isn't the same as my count I stop right there and find out what's wrong. And without that check it's almost impossible to get the number of entries right and it means that at end of a long process it doesn't balance and it's really hard to find the problem. So I have checks like that at each step in the process so by the time I am finished I am very confident that the data is correct and the people who need to use that data can have confidence in it.
Your computer wouldn't work without extensive error correction.
Computers do trillions of operations a second and even near perfection wouldn't let the machine run more than a blink before failure. But there is error correction at every step. When a byte is sent by one channel someplace information is sent by another channel that let's the receiver check whether it's right. If it's not right it is requested again. At the machine level there are error correction circuits that filter errors out of the passing information. At the OS level there are algorithms that do the same thing on the information at that level of abstraction. Software has error correction built in to it's basic operations and now is keeping an eye on US! That's what those darned spelling and grammar checkers are - error correction. And then the person using the computer (like me) has to do error correction at that level of abstraction. Without that error correction computers would make useful doorstops or anchors.
Life would be impossible without error correction and it works at every level like it does in a computer. DNA has to replicate billions of bases with basically perfect accuracy in a messy wet environment with lots of chaos. And each replicating strand is basically enclosed in a cloud of enzymes that detect and repair the inevitable errors. And all living things detect and replace the parts of themselves that are failing. The immune and blood clotting systems are examples of error correcting systems.
When systems are operating at a very high level of abstraction like being able to stand and balance error correction seems to take on a different character.
It starts to be like a thermometer. If it's too cold then turn on the furnace. If it's too cold turn it off. This feedback loop sort of error correction enables abilities like balance that are marvels of sensitivity. And in people balance involves many error correction channel. There are not only the balance organs of our inner ears, there is our sense of vision and the way our body feels. When all these systems are working then a creature is almost impossible to knock over. But try standing on one foot with your eyes closed and your hands crossed firmly over your chest.
In complex systems like an ecosystem there are certainly systems that function as the thermostat type of regulator. For instances, lots of rabbits lead to an overeaten forest and rabbit starvation. The surviving rabbits find so much food that they are in a rabbittish paradise and breed like bunnies. The resultant population does oscillate around an equilibrium point but I'd not call this error correction because there is no proper level of population for rabbits. That is, since at the level of ecosystems it's not reasonable to speak of purpose and without purpose there is no way of speaking of error.
I wonder if we can say the same thing applies to a society - is a society something with no purpose and hence no possibility of error correction? That's sure the way it seems when we look at the absurd hurly burly of politics and economics But don't we feel that that's a problem. A part of the reason we all pay attention to these things is that we sense that there are right and wrong ways that we can deal with the situations we find ourselves in. But we might think of that very chaos as a part of a social error correction system. A chaotic society is very hard to change - any change at all involves influencing millions and millions of people which gives a certain social momentum around a slowly changing mean. The error that this protects us from is the easily expressed whims of the few who think they are powerful.
What do you think?This kind of error correction is conceptually simple