[jcannell]

This is a pretty good summary, but to note this is not a new unsupervised technique - it's a sparse coding method, and sparse coding has been around for more than a decade. Summarizing this paper without mentioning the word sparse coding seems wrong somehow. ;)

[cs702]

You're right, sparse coding is not new -- and neither is the idea of greedy layer-wise training.

But if this works as advertised, these guys must be doing something new.

[saguppa]

But, sadly, it doesn't work as advertised. My hypothesis is that it's extremely difficult to get great results with greedy training. Jointly learning multiple layers from huge datasets is why things started working so well.

[cs702]

Yes, I just saw the retraction.