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I always put meta keywords on my sites pages. But I have heard rumors that you do not have to do this. Should I continue putting keywords on my pages or is it just a waste of time?
This article says, that Google resigned from using META keywords many years ago due to the fact that they are easily abused.
Quote:
Our web search (the well-known search at Google.com that hundreds of
millions of people use each day) disregards keyword metatags
completely. They simply don't have any effect in our search ranking at
present.
Well it's true that crawlers such as Google use much more sophisticated methods than simply META tags to decide PageRank and index pages, but I don't think that's any reason to necessarily remove them or not include them.
Other, less sophisticated crawlers may use it as a legitimate source of information, and so I suppose the only clear answer I can give is: if you don't want to limit your visibility to only the well established search engines which don't rely on the tags, then you might as well still include them. As long as you take into account that there are far more important methods of promoting your site (See Google Webmasters Education for example), you'll be fine.
I know that Google’s search algorithm is mainly based on pagerank. However, it also does analysis and uses the structure of the document H1, H2, title and other HTML tags to enhance the search results.
What is the name of this technique "using the document structure to enhance the search results"?
And are there any academic papers to help me study this area?
The fact that Google is taking the HTML structure into account is well covered in SEO articles however I could not find it in the academic papers.
I think it's called "Semantic Markup"
[...] semantic markup is markup that is descriptive enough to allow us and the machines we program to recognize it and make decisions about it. In other words, markup means something when we can identify it and do useful things with it. In this way, semantic markup becomes more than merely descriptive. It becomes a brilliant mechanism that allows both humans and machines to “understand” the same information. http://www.digital-web.com/articles/writing_semantic_markup/
A more practical article here
http://robertnyman.com/2007/10/29/explaining-semantic-mark-up/
SEO has become almost a religion to some people where they obsess about minutiae. Frankly, I'm not convinced that all this effort is justified.
My advice? Ignore what so-called pundits say and just follow Google's guidelines.
You might be looking for an academic answer but honestly, this isn't an academic question beyond the very basics of how Web indexing works. The reality of a modern page indexing and ranking algorithm is far more complex.
You may want to look at one of the earlier works on search engines. Note the authors' names. You may also want to read Google Patent application 20050071741.
These general principles aside, Google's search algorithm is constantly tweaked based on actual and desired results. The exact workings are a closely guarded secret just to make it harder for people to game the system. Much of the "advice" or descriptions on how Google's search algorithm works is pure supposition.
So, apart from having a title and having well-formed and valid HTML, I don't think you're going to find what you're looking for.
Google very deliberately doesn't give away too much information about its search algorithm, so it's unlikely you will find a definitve answer or academic paper that confirms this. If you're interested from an SEO point of view, just write your pages so they are good for humans and the robots will like them too.
To make a page good for humans, you SHOULD use tags such as h1, h2 and so on to create a hierarchical page outlay... a bit like this...
h1 "Contact Us"
...h2 "Contact Details"
......h3 "Telephone Numbers"
......h3 "Email Addresses"
...h2 "How To Find Us"
......h3 "By Car"
......h3 "By Train"
The difficulty with your question is that if you put something in your h1 tag hoping that it would increase your position in Google, but it didn't match up with other content on your page, you could look like you are spamming. Similarly, if your page is made up of too many headings and not enough actual content, you could look like you are spamming. It's not as simple as add a h1 and h2 tag and you'll go up! That's why you need to write websites for humans, not robots.
I have found this paper:
A New Study on Using HTML Structures to Improve Retrieval
however it is an old paper 1999,
still looking for more recent papers.
Check out
http://jcmc.indiana.edu/vol12/issue3/pan.html
http://www.springerlink.com/content/l22811484243r261/
Some time spent on scholar.google.com might help you find what you are looking for
You can also try searching the 'Computer Science' section of arXiv: http://arxiv.org for "search engine" and the various terms that others have suggested.
It contains many academic papers, all freely available... hopefully some of them will be relevant to your research. (Of course the caveat of validating any paper's content applies.)
Like cletus said follow the google guidelines.
I did a few tests came to the conclusion that title, image alt and h tags the most important. Also worth to mention is google adsense. I had the feeling if you implement these, the rank of your site increase.
I believe what you are interested in is called structural-fingerprinting, and it is often used to determine the similarity of two structures. In Google's case, applying a weight to different tags and applying to a secret algorithm that (probably) uses the frequencies of the different elements in the fingerprint. This is deeply routed in information theory - if you are looking for academic papers on information theory, I would start with "A Mathematical Theory of Communication" by Claude Shannon
I would also suggest looking at Microformats and RDF's. Both are used to enhance searching. These are mostly search engine agnostic, but there are some specific things as well. For google specific guidelines for HTML content read this link.
In short; very carefully. In long:
Quote from anatomy of a large-scale hypertextual erb search engine:
[...] This gives us some limited
phrase searching as long as there are
not that many anchors for a particular
word. We expect to update the way that
anchor hits are stored to allow for
greater resolution in the position and
docIDhash fields. We use font size
relative to the rest of the document
because when searching, you do not
want to rank otherwise identical
documents differently just because one
of the documents is in a larger
font. [...]
It goes on:
[...] Another big difference between
the web and traditional well controlled collections is that there
is virtually no control over what
people can put on the web. Couple
this flexibility to publish anything
with the enormous influence of search
engines to route traffic and companies
which deliberately manipulating search
engines for profit become a serious
problem. This problem that has not
been addressed in traditional closed
information retrieval systems. Also,
it is interesting to note that
metadata efforts have largely failed
with web search engines, because any
text on the page which is not directly
represented to the user is abused to
manipulate search engines. [...]
The Challenges in a web search engine addresses these issues in a more modern fashion:
[...] Web pages in HTML fall into the middle of this continuum of structure in documents, being neither close to free text nor to well-structured data. Instead HTML markup provides limited structural information, typically used to control layout but providing clues about semantic information. Layout information in HTML may seem of limited utility, especially compared to information contained in languages like XML that can be used to tag content, but in fact it is a particularly valuable source of meta-data in unreliable corpora such as the web. The value in layout information stems from the fact that it is visible to the user [...]:
And adds:
[...] HTML tags can be analyzed for what semantic information can be inferred. In addition to the header tags mentioned above, there are tags that control the font face (bold, italic), size, and color. These can be analyzed to determine which words in the document the author thinks are particularly important. One advantage of HTML, or any markup language that maps very closely to how the content is displayed, is that there is less opportunity for abuse: it is difficult to use HTML markup in a way that encourages search engines to think the marked text is important, while to users it appears unimportant. For instance, the fixed meaning of the tag means that any text in an HI context will appear prominently on the rendered web page, so it is safe for search engines to weigh this text highly. However, the reliability of HTML markup is decreased by Cascading Style Sheets which separate the names of tags from their representation. There has been research in extracting information from what structure HTML does possess.For instance, [Chakrabarti etal, 2001; Chakrabarti, 2001] created a DOM tree of an HTML page and used this information to in-crease the accuracy of topic distillation, a link-based analysis technique.
There are number of issues a modern search engine needs to combat, for example web spam and blackhat SEO schemes.
Combating webspam with trustrank
Webspam taxonomy
Detecting spam web pages through content analysis
But even in a perfect world, e.g. after eliminating the bad apples from the index, the web is still an utter mess because no-one has identical structures. There are maps, games, video, photos (flickr) and lots and lots of user generated content. In other word, the web is still very unpredictable.
Resources
Hypertext and the web:
Extracting knowledge from the World Wide Web
Rich media and web 2.0
Thresher: automating the unwrapping of semantic content from the World Wide Web
Information retrieval
Webspam papers
Combating webspam with trustrank
Webspam taxonomy
Detecting spam web pages through content analysis
To keep it painfully simple. Make your information architecture logical. If the most important elements for user comprehension are highlighted with headings and grouped logically, then the document is easier to interpret using information processing algorithms. Magically, it will also be easier for users to interpret. Remember the search engine algorithms were written by people trying to interpret language.
The Basic Process is:
Write well structured HTML - using header tags to indicate the most critical elements on the page. Use logical tags based on the structure of your information. Lists for lists, headers for major topics.
Supply relevant alt tags and names for any visual elements, and then use simple css to arrange these elements.
If the site works well for users and contains relevant information, you don't risk becoming a black listed spammer, and search engine algorithms will favor your page.
I really enjoyed the book Transcending CSS
for a clean explanation of properly structured HTML.
I suggest trying Google scholar as one of your avenues when looking for academic articles
semantic search
I found it interesting that - with no meta keywords nor description provided - in a scenatio like this:
<p>Some introduction</p>
<h1>headline 1</h1>
<p>text for section one</p>
Always the "text for section one" is shown on the search result page.
New tag to use called CANONICAL can now also be used, from Google, click HERE
What work, if any, has been done to automatically determine the most important data within an html document? As an example, think of your standard news/blog/magazine-style website, containing navigation (with submenu's possibly), ads, comments, and the prize - our article/blog/news-body.
How would you determine what information on a news/blog/magazine is the primary data in an automated fashion?
Note: Ideally, the method would work with well-formed markup, and terrible markup. Whether somebody uses paragraph tags to make paragraphs, or a series of breaks.
Readability does a decent job of exactly this.
It's open source and posted on Google Code.
UPDATE: I see (via HN) that someone has used Readability to mangle RSS feeds into a more useful format, automagically.
think of your standard news/blog/magazine-style website, containing navigation (with submenu's possibly), ads, comments, and the prize - our article/blog/news-body.
How would you determine what information on a news/blog/magazine is the primary data in an automated fashion?
I would probably try something like this:
open URL
read in all links to same website from that page
follow all links and build a DOM tree for each URL (HTML file)
this should help you come up with redundant contents (included templates and such)
compare DOM trees for all documents on same site (tree walking)
strip all redundant nodes (i.e. repeated, navigational markup, ads and such things)
try to identify similar nodes and strip if possible
find largest unique text blocks that are not to be found in other DOMs on that website (i.e. unique content)
add as candidate for further processing
This approach of doing it seems pretty promising because it would be fairly simple to do, but still have good potential to be adaptive, even to complex Web 2.0 pages that make excessive use of templates, because it would identify similiar HTML nodes in between all pages on the same website.
This could probably be further improved by simpling using a scoring system to keep track of DOM nodes that were previously identified to contain unique contents, so that these nodes are prioritized for other pages.
Sometimes there's a CSS Media section defined as 'Print.' It's intended use is for 'Click here to print this page' links. Usually people use it to strip a lot of the fluff and leave only the meat of the information.
http://www.w3.org/TR/CSS2/media.html
I would try to read this style, and then scrape whatever is left visible.
You can use support vector machines to do text classification. One idea is to break pages into different sections (say consider each structural element like a div is a document) and gather some properties of it and convert it to a vector. (As other people suggested this could be number of words, number of links, number of images more the better.)
First start with a large set of documents (100-1000) that you already choose which part is the main part. Then use this set to train your SVM.
And for each new document you just need to convert it to vector and pass it to SVM.
This vector model actually quite useful in text classification, and you do not need to use an SVM necessarily. You can use a simpler Bayesian model as well.
And if you are interested, you can find more details in Introduction to Information Retrieval. (Freely available online)
I think the most straightforward way would be to look for the largest block of text without markup. Then, once it's found, figure out the bounds of it and extract it. You'd probably want to exclude certain tags from "not markup" like links and images, depending on what you're targeting. If this will have an interface, maybe include a checkbox list of tags to exclude from the search.
You might also look for the lowest level in the DOM tree and figure out which of those elements is the largest, but that wouldn't work well on poorly written pages, as the dom tree is often broken on such pages. If you end up using this, I'd come up with some way to see if the browser has entered quirks mode before trying it.
You might also try using several of these checks, then coming up with a metric for deciding which is best. For example, still try to use my second option above, but give it's result a lower "rating" if the browser would enter quirks mode normally. Going with this would obviously impact performance.
I think a very effective algorithm for this might be, "Which DIV has the most text in it that contains few links?"
Seldom do ads have more than two or three sentences of text. Look at the right side of this page, for example.
The content area is almost always the area with the greatest width on the page.
I would probably start with Title and anything else in a Head tag, then filter down through heading tags in order (ie h1, h2, h3, etc.)... beyond that, I guess I would go in order, from top to bottom. Depending on how it's styled, it may be a safe bet to assume a page title would have an ID or a unique class.
I would look for sentences with punctuation. Menus, headers, footers etc. usually contains seperate words, but not sentences ending containing commas and ending in period or equivalent punctuation.
You could look for the first and last element containing sentences with punctuation, and take everything in between. Headers are a special case since they usually dont have punctuation either, but you can typically recognize them as Hn elements immediately before sentences.
While this is obviously not the answer, I would assume that the important content is located near the center of the styled page and usually consists of several blocks interrupted by headlines and such. The structure itself may be a give-away in the markup, too.
A diff between articles / posts / threads would be a good filter to find out what content distinguishes a particular page (obviously this would have to be augmented to filter out random crap like ads, "quote of the day"s or banners). The structure of the content may be very similar for multiple pages, so don't rely on structural differences too much.
Instapaper does a good job with this. You might want to check Marco Arment's blog for hints about how he did it.
Today most of the news/blogs websites are using a blogging platform.
So i would create a set of rules by which i would search for content.
By example two of the most popular blogging platforms are wordpress and Google Blogspot.
Wordpress posts are marked by:
<div class="entry">
...
</div>
Blogspot posts are marked by:
<div class="post-body">
...
</div>
If the search by css classes fails you could turn to the other solutions, identifying the biggest chunk of text and so on.
As Readability is not available anymore:
If you're only interested in the outcome, you use Readability's successor Mercury, a web service.
If you're interested in some code how this can be done and prefer JavaScript, then there is Mozilla's Readability.js, which is used for Firefox's Reader View.
If you prefer Java, you can take a look at Crux, which does also pretty good job.
Or if Kotlin is more your language, then you can take a look at Readability4J, a port of above's Readability.js.
I was wondering if using HTML entities in meta tags (like keywords and description) is the best way to go?
Does it influence the indexing from search engines?
I'd put the meta tags contents without entities as long as my charset allows the chars. I researched a bit and I found this on Google Webmasters/Site owners help and the example contains £9.24 not £9.24 nor £9.24
As is true that meta tags aren't a big factor for success, they can be a factor for failure. Indexer robots may detect a try of cheat them by using invalid keywords or description. From Wikipedia:
Early versions of search algorithms
relied on webmaster-provided
information such as the keyword meta
tag, or index files in engines like
ALIWEB. Meta tags provide a guide to
each page's content. But using meta
data to index pages was found to be
less than reliable because the
webmaster's choice of keywords in the
meta tag could potentially be an
inaccurate representation of the
site's actual content. Inaccurate,
incomplete, and inconsistent data in
meta tags could and did cause pages to
rank for irrelevant searches. Web
content providers also manipulated a
number of attributes within the HTML
source of a page in an attempt to rank
well in search engines.
The meta description can be used as the default snippet.
The meta keywords are pretty much completely ignored, but everyone still uses them anyway.
Neither will have much (if any) effect on your ranking, but a good meta description could boost your clickthrough.
Entities make difference only in amateur HTML "parsers" done with regular expressions. They aren't problem for Google.
Meta tags are not ignored. There are still read by Google, so I think, they should be used in the proper way. Google loves pages done in proper way, but remember, that meta tag is one of hundreds things that robots take into consideration.
if there are umlaute dont use entities.
i think, google is indexing the word "bremsbeläge" as "bremsbelaege" and "bremsbeläge".
The meta tag "description" does have an effect on the ranking. It is the description that Google gives in the listing, so this is the most important part that influences people to click on your link. When more people click on your link, Google assumes it has more worth for users in the searches and moves you up.
Does filling out HTML meta description/keyword tags matter for SEO?
This article has some info on it.
A quick summary for keywords is:
Google and Microsoft: No
Yahoo and Ask: Yes
Edit: As noted below, the meta description is used by Google to describe your site to potential visitors (although may not be used for ranking).
Google will use meta tags, but the description, to better summarize your site. They won't help to increase your page rank.
See:
http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=79812
EDIT: #Petr, are you sure that meta tags influence page rank? I am pretty sure that they don't, but if you have some references, I'd love to learn more about this. I have seen this, from the Official Google Webmaster Central Blog, which is what leads me to believe that they don't:
Even though we sometimes use the
description meta tag for the snippets
we show, we still don't use the
description meta tag in our ranking.
Keywords: Useless
All major search engines don't use them at all.
Description: Useful!
Replaces the default text in search engines if there isn't anything better. Use this to describe the page properly. Not perhaps useful for SEO, but it makes your results look more useful, and will hopefully increase click through rates by users.
If you want your users to share your content on Facebook, the meta tags actually come in handy, as Facebook will use this information when styling the post.
See Facebook Share Partners for more information.
Edit; whoops, wrong url. Fixed.
If your pages are part of an intranet then both the keywords and description meta tags can be very useful. If you have access to the search engine crawling your pages (and thus you can specifically look for sepcific tags/markup), they can add tremendous value without costing you too much time and are easy to change.
For pages outside of an intranet, you may have less success with keywords for reasons mentioned above.
The description meta is important as it is displayed ad-verbatim on Google search results below your site title. The absence of which, Google pulls and shows the first few lines of content on SERPs. The description tag allows you to control what SE users see as a page summary before clicking. This helps in increasing your CTRs from Search.
The keyword meta usefulness is still inconclusive, but SEOers continue to use them. Avoid using more than 5-6 keywords in the tag per page to avoid Google from detecting and penalising due to any suspected keyword dumping.
The problem with keyword meta tags is they are a completely unreliable source of information for search engines. The temptation for people to alter search results in their favour with misleading keywords is just too great.
Those are two of the things that are used by search engines. The exact weight of each changes frequently, they are generally regarded; however, as being fairly important.
One thing to note, care should be taken when entering values. The more relevant the keywords and description are to the textual content of the site, the more weight may be given to them. Of course there are no guarantees as nobody outside of the search engine companies really know what algorithms are being used.
This post talks a bit more about some aspects.