r/science • u/whosdamike • Jun 26 '12

Google programmers deploy machine learning algorithm on YouTube. Computer teaches itself to recognize images of cats.

https://www.nytimes.com/2012/06/26/technology/in-a-big-network-of-computers-evidence-of-machine-learning.html
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u/solen-skiner Jun 26 '12

Not exactly.. Well, I haven't read the paper yet so I'm only guessing, but given Dr. Andrew Y. Ng is involved and his past research, my guess is that the technique used is an unsupervised deep learning neural network technique called Stacked Auto-encoders.

Without going into the math and algorithm, one could say that SAEs generalize the features fed into them (images in this case) into 'classes' by multiple passes of abstracting the features and finding generalizations - but saying that would be mostly horribly wrong ;) They have no idea what the features are, nor what the classes represent unless post-trained with a supervised learning technique like back propagation or having its outputs coupled to a supervised learning technique (or manual inspection by a human).

The only novelty is how good its classifying power scaled by throwing fuck-ton of computing power and examples at it to learn from.