# MrHen comments on What is control theory, and why do you need to know about it? - Less Wrong

39 28 April 2009 09:25AM

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Comment author: 28 April 2009 06:28:36PM *  1 point [-]

I imagine you can't even catch a ball unless you can predict where it's going to be.

Mmm... does "you" mean a person or does "you" mean anything? Catching a ball can easily be done without predicting its final location and was discussed in a different thread.

Comment author: 28 April 2009 07:26:47PM 0 points [-]

Mmm... does "you" mean a person or does "you" mean anything? Catching a ball can easily be done without predicting its final location and was discussed in a different thread.

That depends on what you mean by "predict". I don't mean a conscious prediction, I just mean a model that tells you how to get there. Even if that model is an algorithm, it's still a prediction.

Consider the ball player who runs to catch the ball, and then realizes he's not going to make it and stops trying. How is that not a prediction?

Comment author: 28 April 2009 08:17:13PM 0 points [-]

I just mean a model that tells you how to get there.

Oh, okay. I misunderstood what you meant.

Consider the ball player who runs to catch the ball, and then realizes he's not going to make it and stops trying. How is that not a prediction?

That has little to do with what I was talking about. Something that "predicts" by thinking "If I am not holding the ball, move closer" has no concept of being able to "make it" to the landing spot. It couldn't care less where the ball ends up. All it needs to know is if it is currently holding the ball and how to get closer. The "how to get closer" is the predictor.

Comment author: 28 April 2009 09:37:47PM *  0 points [-]

That has little to do with what I was talking about. Something that "predicts" by thinking "If I am not holding the ball, move closer" has no concept of being able to "make it" to the landing spot. It couldn't care less where the ball ends up. All it needs to know is if it is currently holding the ball and how to get closer. The "how to get closer" is the predictor.

As I said, I understand you can make a control system that works that way. I'm just saying that humans don't appear to work that way, and possibly cortically-driven behaviors in general (across different species) don't work that way either.