Technically, Yahoo's information on your site is derived from the data you submit. Keywords are in the title or in the first few words of your web page. Keywords are close to one another in your page. Keywords are used more than once in your page. Capitalize any keywords that the searcher may capitalize when searching for your site.
Searches favor sites with keywords in the title and then in the text of the site.
It also favors keywords that are contained in complete sentences. Pages with keywords in the title and then in the text are given preference. Hotbot also uses meta tags. Pages with keywords at the beginning of the page or in the title do well. Pages with a high frequency of keywords in the text of the page also tend to rank higher.