Each of the following components are critical pieces to a site's ability to be crawled, indexed, and ranked by search engine spiders. When properly used in the construction of a website, these features give a site/page the best chance of ranking well for targeted keywords.

Accessibility

An accessible site is one that ensures delivery of its content successfully as often as possible. The functionality of pages, validity of HTML elements, uptime of the site's server, and working status of site coding and components all figure into site accessibility. If these features are ignored or faulty, both search engines and users will select other sites to visit.

The biggest problems in accessibility that most sites encounter fit into the following categories. Addressing these issues satisfactorily will avoid problems getting search engines and visitors to and through your site.

• Broken Links - If an HTML link is broken, the contents of the linked-to page may never be found. In addition, some surmise that search engines negatively degrade rankings on sites & pages with many broken links.

• Valid HTML & CSS - Although arguments exist about the necessity for full validation of HTML and CSS in accordance with W3C guidelines, it is generally agreed that code must meet minimum requirements of functionality and successful display in order to be spidered and cached properly by the search engines.

• Functionality of Forms and Applications - If form submissions, select boxes, javascript, or other input-required elements block content from being reached via direct hyperlinks, search engines may never find them. Keep data that you want accessible to search engines on pages that can be directly accessed via a link. In a similar vein, the successful functionality and implementation of any of these pieces is critical to a site's accessibility for visitors. A non-functioning page, form, or code element is unlikely to receive much attention from visitors.

• File Size - With the exception of a select few documents that search engines consider to be of exceptional importance, web pages greater than 150K in size are typically not fully cached. This is done to reduce index size, bandwidth, and load on the servers, and is important to anyone building pages with exceptionally large amounts of content. If it's important that every word and phrase be spidered and indexed, keeping file size under 150K is highly recommended. As with any online endeavor, smaller file size also means faster download speed for users - a worthy metric in its own right.

• Downtime & Server Speed - The performance of your site's server may have an adverse impact on search rankings and visitors if downtime and slow transfer speeds are common. Invest in high quality hosting to prevent this issue.

URLs, Title Tags & Meta Data

URLs, title tags and meta tag components are all information that describe your site and page to visitors and search engines. Keeping them relevant, compelling and accurate are key to ranking well. You can also use these areas as launching points for your keywords, and indeed, successful rankings require their use.

The URL of a document should ideally be as descriptive and brief as possible. If, for example, your site's structure has several levels of files and navigation, the URL should reflect this with folders and subfolders. Individual pages' URLs should also be descriptive without being overly lengthy, so that a visitor who sees only the URL could have a good idea of what to expect on the page. Several examples follow:

Comparison of URLs for a Canon Powershot SD400 Camera

Amazon.com - http://www.amazon.com/gp/product/B0007TJ5OG/102-8372974-
4064145?v=glance&n=502394&m=ATVPDKIKX0DER&n=3031001&s=photo&v=glance

Canon.com - http://consumer.usa.canon.com/ir/controller?
act=ModelDetailAct&fcategoryid=145&modelid=11158

DPReview.com - http://www.dpreview.com/reviews/canonsd400/

With both Canon and Amazon, a user has virtually no idea what the URL might point to. With DPReview's logical URL, however, it is easy to surmise that a review of a Canon SD400 is the likely topic of the page.

In addition to the issues of brevity and clarity, it's also important to keep URLs limited to as few dynamic parameters as possible. A dynamic parameter is a part of the URL that provides data to a database so the proper records can be retrieved, i.e. n=3031001, v=glance, categoryid=145, etc.

Note that in both Amazon and Canon's URLs, the dynamic parameters number 3 or more. In an ideal site, there should never be more than two. Search engineer representatives have confirmed on numerous occasions that URLs with more than 2 dynamic parameters may not be spidered unless they are perceived as significantly important (i.e. have many, many links pointing to them).

Well written URLs have the additional benefit of serving as their own anchor text when copied and pasted as links in forums, blogs, or other online venues. In the DPReview example, a search engine might see the URL http://www.dpreview.com/reviews/canonsd400/ and give ranking credit to the page for terms in the URL like dpreview, reviews, canon, sd, 400. The parsing and breaking of terms is subject to the search engine's analysis, but the chance of earning this additional credit makes writing friendly, usable URLs even more worthwhile.

Title tags, in addition to their invaluable use in targeting keyword terms for rankings, also help drive click-through-rates (CTRs) from the results pages. Most of the search engines will use a page's title tag as the blue link text and headline for a result (see image below), and thus it is important to make them informative and compelling without being overly "salesy". The best title tags will make the targeted keywords prominent, help brand the site, and be as clear and concise as possible.

Examples and Recommendations for Title Tags

Page on Red Pandas from the Wellington Zoo:
- Current Title: Red Panda
- Recommended: Red Panda - Habitat, Features, Behavior | Wellington Zoo

Page on Alexander Calder from the Calder Foundation:
- Current Title: Alexander Calder
- Recommended: Alexander Calder - Biography of the Artist from the Calder Foundation

Page on Plasma TVs from Tiger Direct:
- Current Title: Plasma Televisions, Plasma TV, Plasma Screen TVs, SONY Plasma TV, LCD TV at TigerDirect.com
- Recommended: Plasma Screen & LCD Televisions at TigerDirect.com

For each of these, the idea behind the recommendations is to distill the information into the clearest, most useful snippet while retaining the primary keyword phrase as the first words in the tag. The title tag provides the first impression of a web page and can either serve to draw the visitor in or compel him or her to choose another listing in the results.

Meta Tag Recommendations:

Meta tags once held the distinction of being the primary realm of SEO specialists. Today, the use of meta tags, particularly the meta keywords tag, has diminished to an extent that search engines no longer use them in their ranking of pages. However, the meta description tag can still be of some importance, as several search engines use this tag to display the snippet of text below the clickable title link in the results pages.

In the image to the left, an illustration of a Google SERP (Search Engine Results Page) shows the use of the meta description and title tags. It is on this page that searchers generally make their decision as to which result to click, and thus, while the meta description tag may have little to no impact on where a page ranks, it can significantly impact the # of visitors the page receives from search engine traffic. Note that meta tags are NOT always used on the SERPs, but can be seen (at the discretion of the search engine) if the description is accurate, well-written, and relevant to the searcher's query.

Search-Friendly Text

Making the visible text on a page "search-friendly" isn't complicated, but it is an issue that many sites struggle with. Text styles that cannot be indexed by search engines include:

• Text embedded in a Java Application or Macromedia Flash file
• Text in an image file - jpg, gif, png, etc
• Text accessible only via a form submit or other on-page action

If the search engines can't see your page's text, they cannot spider and index that content for visitors to find. Thus, making search-friendly text in HTML format is critical to ranking well and getting properly indexed. If you are forced to use a format that hides text from search engines, try to use the right keywords and phrases in headlines, title tags, URLs, and image/file names on the page. Don't go overboard with this tactic, and never try to hide text (by making it the same color as the background or using CSS tricks). Even if the search engines can't detect this automatically, a competitor can easily report your site for spamming and have you de-listed entirely.

Along with making text visible, it's important to remember that search engines measure the terms and phrases in a document to extract a great deal of information about the page. Writing well for search engines is both an art and a science (as SEOs are not privy to the exact, technical methodology of how search engines score text for rankings), and one that can be harnessed to achieve better rankings.

In general, the following are basic rules that apply to optimizing on-page text for search rankings:

• Make the primary term/phrase prominent in the document - Measurements like keyword density are useless, but general frequency can help rankings.

• Make the text on-topic and high quality - Search engines use sophisticated lexical analysis to help find quality pages, as well as teams of researchers identifying common elements in high quality writing. Thus, great writing can provide benefits to rankings, as well as visitors.

• Use an optimized document structure - The best practice is generally to follow a journalistic format wherein the document starts with a description of the content, then flows from broad discussion of the subject to narrow. The benefits of this are arguable, but in addition to SEO value, they provide the most readable and engaging informational document. Obviously, in situations where this would be inappropriate, it's not necessary.

• Keep text together - Many folks in SEO recommend using CSS rather than table layouts in order to keep the text flow of the document together and prevent the breaking up of text via coding. This can also be achieved with tables - simply make sure that text sections (content, ads, navigation, etc.) flow together inside a single table or row and don't have too many "nested" tables that make for broken sentences and paragraphs.

Keep in mind that the text layout and keyword usage in a document no longer carries high importance in search engine rankings. While the right structure and usage can provide a slight boost, obsessing over keyword placement or layout will provide little overall benefit.

Information Architecture

The document and link structure of a website can provide benefits to search rankings when performed properly. The keys to effective architecture are to follow the rules that govern human usability of a site:

• Make Use of a Sitemap - It's wise to have the sitemap page linked to from every other page in the site, or at the least from important high-level category pages and the home page. The sitemap should, ideally, offer links to all of the site's internal pages. However, if more than 100-150 pages exist on the site, a wiser system is to create a sitemap that will link to all of the category level pages, so that no page in a site is more than 2 clicks from the home page. For exceptionally large sites, this rule can be expanded to 3 clicks from the home page.

• Use a Category Structure that Flows from Broad > Narrow - Start with the broadest topics as hierarchical category pages, then expand to deep pages with specific topics. Using the most on-topic structure tells search engines that your site is highly relevant and covers a topic in-depth.

For more information on segmenting document structure and link hierarchies, see Dr. Garcia's excellent guide to on-topic analysis.

Canonical Issues & Duplicate Content

One of the most common and problematic issues for website builders, particularly those with larger, dynamic sites powered by databases, is the issue of duplicate content. Search engines are primarily interested in unique documents and text, and when they find multiple instances of the same content, they are likely to select a single one as "canonical" and display that page in their results.

If your site has multiple pages with the same content, either through a content management system that creates duplicates through separate navigation, or because copies exist from multiple versions, you may be hurting those pages' chances of ranking in the SERPs. In addition, the value that comes from anchor text and link weight, through both internal and external links to the page, will be diluted by multiple versions.

The solution is to take any current duplicate pages and use a 301 re-direct (described in detail here) to point all versions to a single, "canonical" edition of the content.

One very common place to look for this error is on a site's homepage - oftentimes, a website will have the same content on http://www.url.com, http://url.com, and http://www.url.com/index.html. That separation alone can cause lost link value and severely damage rankings for the site's homepage. If you find many links outside the site pointing to both the non-www and the www version, it may be wise to use a 301 re-write rule to affect all pages at one so they point to the other