Latent Semantic Indexing (LSI) can also be used as Latent semantic Analysis (LSA). Tutorial of LSI is discussed below. It is used to find out the meaning or concept of the documents available. Each word represents some concept and the concept keeps on changing as words in the document changes. LSI keywords helps to find out the relation between two keywords or it helps to co relate similar concept between two keywords.
Example of LSI keywords (Category : Media)
Tutorial 1 : Radio (Keyword)
Concept: News, advertisement, Information, Entertainment, Music, Songs
Tutorial 2 : Television (Keyword) –
Concept: News, movies, Entertainment, Information, Music, Songs, Advertisement
So in the above example Both keywords Radio and Television share some common concept and hence according to google they are related to each other in terms of concept or context. These keywords are know as semantic keywords.
Radio and Television are both different entities but the attributes or concept co relate with each other hence they can be used as latent semantic keywords.
So if two articles are compared with each other, then lots of keywords are used which might be different but if the concept or attributes matches then those two articles are related to each other.
It is important to perform proper keyword research by following suggested methodology to write quality articles to rank documents in google search results by Search engine optimization (SEO) in order to get more traffic to a website.