HI All I want to calculate keyword density, but I am not sure which one is correct. Could you help me please. Or, if you have another technique please teach me please.
( Thai silk Exporter silk exporter, SILK EXPORTER, Silk Exporter Thai silk Exporter is the biggest silk wholesaler in Thailand. Thai silk Exporter provides the various types of Thai silk fabric from every part of Thailand with 100% satisfy guaranteed.)
1) There are 6 keywords "silk exporter" and total word is 39 words. So, keyword density should be = 6*100/39 = 15.38% Or, it should be = (6*2*100)/39 = 30.79% (2 is a number of word in keyword phase)
2) How many keyword density in the <head> and <body> section should I use?
The link numediagirl provided should take care of the math for you.
Most people probably aren't willing to give out the perfect keyword weight, I would recommend checking out the weights of pages that are ranking well on various engine and figure out what works on each engine.
Things to keep in mind:
1 - determine the weights of words in a phrase seperately (many engines give more weight to less common words)
2 - test the engines for variables like partial matching and exact matching before you compare your pages.
>determine the weights of words in a phrase seperately (many engines give more weight to less common words)
If the weighting of the words is dependent on how common they are, does this eliminate the possibility that the relative position within a phrase has any significance? Would this mean that whether a word is the first, second or third word in a three word phrase is not considered to be a factor at all?
"does this eliminate the possibility that the relative position within a phrase has any significance?"
I'm not saying that at all, weight and prominence (relative position) should be judged seperately. With something like exact matching, the order of the words in a key phrase will be extremely important. You should also keep in mind the position of the keywords on the page (general rule is that the closer to the top the better), as well as the location of your keywords within specific areas of text. (If a two word (non-exact matching) search is performed on AV they will give a boost to pages that have the two words located within 10 words of each other).