Keyword Factors Used in the Algorithm
The following factors play a part in the portion of the Google algorithm that determines page relevancy. Google looks at the following keyword factors and assigns a relevancy score for each page of your site. The factors are listed in approximate order of importance, however, like all factors in the Google algorithm, this is subject to change.
Keyword Proximity
Google looks at individual words that make up phrases. Keyword proximity is a measure of word order and closeness. The closer all words in a keyword phrase are together, and in the correct order, the better.
Obviously, exact matches score the best. As an example, say someone does a search on “country house plans”. Google will assign a higher score if your page contains “country house plans” than if it contains “country and farm house plans”. For the latter, all three words are contained on the page, so the page would receive some score, but since this is an inexact match (there are words in between “country and “house”), the page score would be lower than for the exact match of country house plans.
Keyword Placement
This measures where on the page keywords are located. Google looks for keywords in the page title, in headings, in body text, in links, in image ALT text and in drop-down boxes.
Keyword Prominence
A measure of how early or high up on a page the keywords are found. Having keywords in the first heading and in the first paragraph (first 20 words or so) on a page are best.
Keyword Density
Also known as keyword weight, the number of times a keyword is used on a page divided by the total number of words on the page. There is some confusion over keyword density. Part of this stems from the fact that different software programs look at different parts of the page and calculate this differently.
There doesn’t seem to be an ideal density value for Google. Just don’t spam. In other words, don’t fill your pages up needlessly with your keywords - not only will customers think your site is amateurish, but Google may penalize you
Keyword density used to be more important in the past for search engines, and you may still find books that stress the importance of this factor. For Google, it is not important so don't get hung up on it.
Keyword Format
A measure of whether keywords are bolded or italicized on the page. The best place to do this is in the first paragraph of the page. This isn’t a real important factor, but every little bit helps.
How and Where to Use Keywords
Don't try to use all of your keywords on the home page - rather focus only on your Primary Keyword Phrase and your best Secondary Keyword. Use your product or service pages to focus on the more specific keyword.
You will likely want to use the plural form of your keywords. However, you need to verify this using KeywordDiscovery or WordTracker as sometimes the singular form of a word is searched on more often.
Google treats hyphenated words as two words: “house-plans” is the same as “house plans” on Google. However, words connected by an underscore or slash, such as “house_plans” and “house/plans” are treated as a single word “houseplans” currently.
Google is not case-sensitive, so HOUSE PLANS, House Plans, house plans, and HoUsE pLaNs are all treated the same.
The Importance of Title Text
There is one place on a web page where your keywords MUST be present, and that is in the page title, which is everything between the
Correct use of keywords in the title of every page of your website is important to Google – particularly for the home page. If you do nothing else to optimize your site, do this!
The "Keywords" META tag is ignored by Google. Concentrate your efforts on the title for each page, making sure they contain the best keywords for the content of each page.
The title shouldn’t consist of much more than about 9 words or 60 characters, with your keywords used toward the beginning of the title. Since Google is looking for relevant keywords in the title, this means you should NOT include your company name in the title unless your company name is so well known as to be a keyword in it’s own right with instant name recognition – like Disney, Nike, or Yahoo. If you must include your company name in the title, put it at the end. In addition, each page title should be unique – don’t duplicate titles on pages.
Improper or nonexistent use of titles in web pages keep more websites out of top rankings on Google than any other factor except for a lack of quality links from other websites that point to your site.
The following table shows both the improper and proper use of titles for a website that sells house plans. You undoubtedly have seen numerous websites that use “Home” as the title of their home page. Google may think these sites are about homes!
As you can see, you should use relevant keywords in every title of every page of your site. Most people get this wrong. Do a search for “Welcome to”, “Home”, “Home page”, “Untitled Document”, or “index.html” and you’ll see what I mean about incorrect use of TITLE text.
Now a days keywords density is very important factor now a days from that penguin update as we need to be focus on content as well as. click here for further more