Rather than attempting to go into more complex details, entire concepts involving a great deal of learning and study are simply accompanied by some hand waving, a few magic words, and hopes (promises?) that this will produce a rabbit out of a hat.

I would consider it a matter of marketing (explaining?) complex knowledge to people who don’t even understand the fundamental terms being used (and sometimes, those doing the marketing/explaining may have gaps in their knowledge as well).

In his defense, he does build in some caveats, explaining that giving an accurate presentation would take a great deal more time and effort. That being said, some of the errors are nails-on-a-chalkboard, throw-something-through-my-monitor (to use the technical terms) bad… He doesn’t seem to know what stemming is, for one jaw dropper, and blatantly confuses stemming and lexemes (as if they were interchangeable concepts), before declaring that his lack of understanding cancels out a third, unrelated, concept.

Whatever form of Semantic Analysis (SA) Google is using & you are can be sure they are using some type of SA algorithms it’s way beyond LSI as described by Mr. Rohde. I actually find it humorous (at best) that Mr. Rohde fixates on LSI which is the begining of the SA story. Since LSI was developed many other forms of SA have become prominent. One must remember like ANY other underlying algorithm whatever from of SA they are using simply a tool in a very large box.

I’d love to hear him explain in detail how LSI “claims” to handle synonyms and word forms with math and then explain how it does not.

I think one of his issues is he is focusing on 1 algorithm and not taking into account all the other pieces that surround it to maximize its effectiveness. Nothing in Information Retrieval & Information Extraction lives in a bubble, there is no “magic” bullet that one plugs in and bang you are replicating Google.

Finally I do not have a crystal ball into Google’s complete stack & unless I’m really mistaken neither does Mr. Rohde, so talking as an authority on the how & what algorithmically they are doing is silly. This is highlighted by his use of the “Social LSI” concept, while it sounds neat it’s something I have never heard of or can find any reference to. As a practitioner of Statistical NLP which LSI and like technologies are a part of I am horrified by these 2 videos.

Watched those videos about LSI and Google. In the first video the SEO guy explains how LSI works and tries prove that Google is not using simple LSI as he described. In the second video he introduces a new term “Social LSI” that I haven’t heard it before. I’m sure Google is not using classical LSI approach. Probably, they have conceptual and meaningful approaches instead of words or links otherwise; it’d be easy to implement a search engine.

Let’s see what will happen… If he is right or an ex google employee, there would be a discussion about it.