For years many SEOs fooled their own peers with the assertion that LSI was something new that Google implemented. Some even have claimed LSI was a proprietary algorithm from Google. I’ve spent sooooo many years debunking all this crap and few other urban legends from unscrupulous SEOs.
In this Thanksgiving Day I thank that all these myths have been debunked to no end: LSI-rank correlations, LDA-rank correlations, KD-rank correlations, additiveness of correlation coefficients, blah, blah, blah… I thank also that along came this: http://infolab.stanford.edu/~sergey/349/
Known from the onset by Google.
A cost effective implementation in a large scale and dynamic environment as the Web is?