Summary:
This articles explains everything you need to know about keywords and key-phrases in SEO. From keyword density and prominence, to strategies on how to deal with keyword ambiguity.
Keywords:
keyword, seo, keyphrase, density, keyword prominence
Article Body:
<strong>Density and Prominence</strong>
<p>Keyword density is a measure of how much emphasis (weight) a
keyword is given within the content of a page. Most of the emphasis
of a page is assigned to the text at the start of the page, at the
end of the page and within these tags: <title>, <h1>,
<a>, <img alt="" />, <strong> and <em> (up
to 3 or 4 times).</p>
<p>Never waste a precious strong/em tag on content that isn’t
a bunch of keywords. You can use CSS to achieve any visual effect
you want. You should only use those tags to put emphasis on a
keyword/key-phrase.</p>
<p>Keyword prominence is a measure of how important a word is
within its context – in other words, how close it is to the
beginning of the sentence. E.g.: the word ‘car’ is more
prominent in ‘car sale London’ (at the start) than in
‘London car sale’ (at the end).</p>
<p>Keyword prominence and density are 2 concepts applied to every
aspect of your website: URLs, headings, keywords, links, etc. Keep
these 2 ideas in mind as you read through the rest of this article
– they apply to absolutely everything.</p>
<strong>Keywords/Key-phrases</strong>
<p>A keyword is any word that accurately describes your content. A
key-phrase is a combination of keywords.</p>
<p>Stop words are those considered too ‘common’ or
‘vague’, which are ignored in search terms (with
exceptions, but let’s leave it at that for this article). You
may think they’re harmless since they’re ignored, but
stop words can be seriously damage your SEO strategy by occupying a
huge amount of keyword density and prominence within key-phrases in
titles, headings, URLs, links, etc… Example:</p>
<p style="margin-left: 36pt;">Car sales in London = car sales has
50% density, 100% prominence Car sales London = car sales has 66%
density, 100% prominence London car sales = car sales has 66%
density, 66% prominence</p>
<p>When writing up key-phrases, try to write in a newspaper
headline style and miss out common words such as ‘the’,
‘a’, ‘on’, ‘of, ‘in’,
‘you’, ‘me’, ‘he’,
‘it’, etc…</p>
<p>PS.: There are too many stop words in the English language so I
won’t put a list here, but I do have a list if anyone wants
it.</p>
<strong>Keyword Ambiguity</strong>
<p>Search engines are aware of these ambiguities so you'd only be
shooting yourself in the foot if you tried to cover both. Take
"<a href=
"http://www.google.co.uk/search?hl=en&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=xmas+trees+delivered&spell=1"
target="_blank">xmas trees delivered</a> " and "<a href=
"http://www.google.co.uk/search?hl=en&q=christmas+trees+delivered&btnG=Search&meta="
target="_blank">christmas trees delivered</a> " for example. The
word <i>xmas</i> never appears the site's content, but
pinesandneedles.com still ranks top for either of these 2 search
phrases. I find this difficult to explain, but here's why:<i>(using
xmas, christmas and some imaginary numbers)</i></p>
<p style="margin-right: 36pt; margin-left: 36pt;"><u>When you are
strict and avoid ambiguity:</u> Let's say that you only use
"christmas" throughout the site, it ends up with a prominance of
10. (<i>just some number to illustrate this example</i> ). When a
user searches for something with the word "xmas", the search
engines will consider both "xmas" and "christmas" equaliy, so you
end up being a very likely match for their search.<br>
<br>
<u>When you go with the flow and cover every possibility:</u> Let's
say you've used the words 'xmas' and 'christmas' equaly thorought
the website and they each end up with prominance 5. (<i>just some
number to illustrate this example, but smaller than the number on
the previous example</i> ) When a user searches for something with
the word "xmas", the search engines will consider both "xmas" and
"christmas", but you are not as likely to match either, because
you've distributed the prominence between 2 phrases.</p>
<p>When it comes to ambiguous words, it's always best to leave the
search engines to deal with it their own way. Just do your bit by
being clear and consistent.</p>