The following definitions are for the most common terms found in articles written about Latent Semantic Indexing. If your goal is to rank higher in today's search engine environment, it is important to understand the new concepts being discussed.

1. Latent Semantic Indexing: is the latest attempt by Google, and other search engines, to rank websites based on a more natural, or human, approach. Instead of rating sites using keyword density and links, more weight is now being given to sites that are based around a central theme. Importance: LSI is here to stay so new optimization techniques must be used which conform to this new technology if higher search engine rankings are to be obtained.

2. Latent: that which is present but cannot be seen.

3. Semantic: relating to the different meanings of words.

4. Analysis: an investigation to determine essential features and relationships.

5. LSI: the abbreviation often seen for Latent Semantic Indexing.

6. Keyword Stuffing: the practice of using one, or more, keywords over-and-over to trick the search engines into rewarding the website with a higher ranking. For example: The man walked his dog to the dog park where he saw many other dogs. The overuse of the word "dog" is not natural and is only intended to help the site rank higher for the keyword "dog".

7. Keyword Density: the percentage a particular keyword is used in relation to all the words used. For example: in the sentence above, the word "dog" is used three times out of a total number of fifteen words. The keyword density for the sentence is: 3/15, or 20%.

8. Themed website: a website built around a central theme using many inter-related keywords. For example: a themed website about barbecues might be expected to also contain such words as "gas"," patio", "starter fluid", "charcoal", and "ribs". Importance: old optimization techniques of keyword stuffing and striving for a specific keyword density are no longer useful. Today a new approach is needed--websites must be constructed around themes instead of around individual keywords.

9. Theme bleeding: a website which contains content not related to the website's central theme. For example: a travel website may contain articles about different countries which, in effect, distract from the website's core theme.

10. Synonym: a word which has the same, or almost exactly the same meaning, as another word. For example: car and automobile.

11. Polysemy: a word or phrase which has two or more separate meanings. For example: "bank" could be a financial institution or a river bank, depending on the context it is used in.

12. Lexical Database: a database in which words are grouped into sets that relate to a distinct concept. WordNet has a large, free, English lexical database. Importance: search engines are becoming smarter with the new LSI technology. At one time it was difficult for a search engine to distinguish between words with the same spelling but different meanings--a polysemy--but those days are over. Today websites must be built using a variety of keywords--synonyms, plurals, different tenses of verbs--anything that helps develop a central theme. The use of lexical databases and other tools can help collect these necessary terms and phrases.

13. Inbound Links: a hyperlink from a separate website which points to your site.

14. Outbound links: a hyperlink on your website which points to a different site.

15. Reciprocal Linking: the mutual exchange of links between two websites. In the case of reciprocal linking your site would have both an inbound link from, and an outbound link to, a particular website. Importance: with the new LSI technology, reciprocal linking has lost most of its usefulness.

16. Anchor Text: the clickable text in a hyperlink. If the anchor text is clicked on it will take you to a new site. For example: the anchor text could simply be LSI instead of the complete URL. Importance: It is now necessary to develop inbound links to a number of your site's internal pages by using different anchor texts instead of having all the inbound links go to your homepage.

17. Algorithm: a fixed list of distinct instructions to follow; a formula. The search engines use algorithms to determine which web pages they will return for a search made on a particular keyword or keyword phrase.

18. Boolean: a search method used by search engines which uses three logical operators, "or", "and", and "not". For example: there could be a search for "dog", "dog and cat", or "dog or cat". This type of search does will return websites based on keywords, not themes.

19. Taxonomy: the science or technique of classification and categorization.

20. Dynamic Taxonomy: the process for searching and retrieving information from large, diverse, databases.