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Old 04-09-2013, 02:55 PM
Moobb Moobb is offline
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Default *ANSWER* q6

I am confused on the answer for Q6. I can see that all choices have the same score, but I was assuming that not all of them would be valid hypothesis. I don't see how the opposite of XOR can agree with the 5 points in the dataset D. Isn't it required that the hypothesis would match those points??
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Old 04-09-2013, 03:22 PM
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yaser yaser is offline
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Default Re: *ANSWER* q6

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Originally Posted by Moobb View Post
I am confused on the answer for Q6. I can see that all choices have the same score, but I was assuming that not all of them would be valid hypothesis. I don't see how the opposite of XOR can agree with the 5 points in the dataset D. Isn't it required that the hypothesis would match those points??
You are right that in learning we try to match the training points. The message of this problem is that regardless of whether you are doing something intelligent or otherwise, there is noting that can be learned outside the training sample in a deterministic sense. To make the message crisp, the problem considers some 'crazy' training schemes in the mix.
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Old 04-09-2013, 03:29 PM
Elroch Elroch is offline
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Default Re: *ANSWER* q6

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Originally Posted by Moobb View Post
I am confused on the answer for Q6. I can see that all choices have the same score, but I was assuming that not all of them would be valid hypothesis. I don't see how the opposite of XOR can agree with the 5 points in the dataset D. Isn't it required that the hypothesis would match those points??
It is, and it can be presumed they do from the question. Given that the values of the function on D are already known, the definitions must only apply to the remaining 3 points.

[ apologies for cross-posting against the more authoritative answer above ]
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Old 04-09-2013, 03:53 PM
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Default Re: *ANSWER* q6

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apologies for cross-posting against the more authoritative answer above
Thank you and all other participants who take the time to answer questions and make the discussion lively. Different points of view are always welcome. Just look at my signature.
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Old 04-09-2013, 04:38 PM
Moobb Moobb is offline
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Default Re: *ANSWER* q6

Thank you! Must say that both answer 'features' were fundamental in order I could properly 'classify' the origin of my confusion about the question!
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Old 09-02-2015, 10:46 PM
henry2015 henry2015 is offline
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Default Re: *ANSWER* q6

I just want to check my understanding at a different angle.

Is it true that the score is 1 x 3 + 3 x 2 + 3 x 1 + 1 x 0 for all?

And what idea behind this question is trying to pass to the students? Just trying not to miss the most important point in this question.

Thanks!
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Old 09-03-2015, 12:42 AM
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Default Re: *ANSWER* q6

Correct.

The idea is that, outside the training set, no "learning" is possible if we take a deterministic view. This is a formal version of the puzzle given at the end of Lecture 1.
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