Latent Semantic Indexing and Analysis

Slide 1: http://www.dotcominfoway.com/ Latent Semantic Analysis & Indexing By Mercy Livingstone. 1

Slide 2: http://www.dotcominfoway.com/ What is latent semantic indexing? Origin of LSI LSI and Search Engines Why LSI introduced into Natural Search Result . LSA – Latent Semantic Analysis LSA with an Example Why LSI important to your SEO activities? Implementing LSI in your website 2

Slide 3: http://www.dotcominfoway.com/ What is latent semantic indexing? Latent Semantic Indexing helps to retrieve accurate information from the very large data base. Invented for information Retrieval in Late 1980’s . The contexts in which certain word exists or does not exits determine the similarity of the document. Closely models humans learning, especially the manner in which people learn a language and acquire a vocabulary. 3

Slide 4: http://www.dotcominfoway.com/ Origin of LSI LSI invented to help in digital libraries such as in varsities to get the exact information. Example, . Students looking for a tutorial may not find a e-book under same theme since that is a different phrase even though the e-book have required content. (E- book, Manual, Tips, Tutorial, Guide) LSI in SE Language: Latent semantic indexing allows a search engine to determine what a page is about outside of specifically matching search query text. LSI gives the search engines the ability to provide its users a more relevant list of options to choose from 4

Slide 5: http://www.dotcominfoway.com/ LSI and Search Engines One of the ways LSI has changed the way Search Engines’ looks at sites is a shift from "keyword" to "themes". Initially, search engines would look solely for the presence and . frequency of keywords on a webpage to determine relevancy >> Poor Results Humans are not looking for pages that contain specific keywords, they are looking for sites build around a theme. Ex, New Wind Turbine, New Wind Turbine House Installation 5

Slide 6: http://www.dotcominfoway.com/ LSI and Search Engines (Cont…) Applied Semantics >> http://www.appliedsemantics.com/ Applied Semantics created this concept to find relevant content to display advertisements. Google acquired them in 2003 April to use this concept in Google Adsense. . Google first used this in ad sense to display relevant ads. 6

Slide 7: http://www.dotcominfoway.com/ Why LSI Introduced in Natural Search Results A conventional search engine that bases its results on 'keyword only' analysis may not give the best results. This is because the older search engine programs cannot tell the difference between:  Similar words with different meanings. e.g.: Dice - Die (dice plural) - Die (as in dead) - Die (as in mould) or Router (wood shaper) - Router (internet connectivity)  Words that are similar in meaning but spelled differently, e.g. : sickness - vomiting  Singular and plural forms of words, ex: dice/die, dog/doggies,  Words with similar roots, such as ‘Education' ‘Educational,' 7

Slide 8: http://www.dotcominfoway.com/ LSA – Latent Semantic Analysis Compares Words in a Paragraph Compare the paragraph with the rest of the Page Compares the page with the rest of pages in the website Make a decision on the theme of the Website 8

Slide 9: http://www.dotcominfoway.com/ LSA With Example Dog Puppy, Fat Puppy Health, Child Puppy breeding tips, Dog Training Website Theme > Dog 9

Slide 10: http://www.dotcominfoway.com/ Why LSI important to your SEO activities? Search engines such as Google do try to figure out phrase relationships when processing queries, improving the rankings of pages with related phrases. . Ex, Tiger Woods, Education, White House Pages that are too focused on one phrase tend to rank worse than one would expect (sometimes even being filtered out for what some SEOs call being over-optimized) Pages that are focused on a wider net of related keywords tend to have more stable rankings 10

Slide 11: http://www.dotcominfoway.com/ Implementing LSI in your website:  Develop themed sites on a broad scale rather than centering around one keyword.  Instead of keyword stuffing or “keyword optimization”, strive for more naturally worded and written pages.  With regards to your keywords, try to include synonyms, related words, plurals, and various tenses whenever possible throughout your site. Use, ~(keyword), will give you the related words.  When establishing inbound links, be sure that they do not all go to the same keyword; have inbound links go to a number of different keywords and relevant terms within your site. 11

Slide 12: http://www.dotcominfoway.com/ Implementing LSI in your website: Do not bother seeking irrelevant reciprocal links. Use variations of your keyword and synonyms. That makes it easier for search engines to determine the topic of your site. / LSI does exist, but not in the form that Google would have us believe, and not in any form that you can use to make your website ‘LSI compliant’ 12

Slide 13: http://www.dotcominfoway.com/ Find Related Words http://wordnet.princeton.edu/perl/webwn http://www.gorank.com/seotools/ontology http://thesaurus.reference.com 13