Friday, April 22, 2011

Alt Attribute & Search engine optimization

SEO Optimization images has become increasingly more important in SEO (Seo optimization) for websites. The ALT attribute is a critical step that is sometimes forgotten. This can be a lost chance of better rankings.


In Google's webmaster guidelines, they advise the use of alternative text for that images in your web site:

Images:. Use the alt attribute to supply descriptive text. In addition, we recommend using a human-readable caption and descriptive text round the image.

Why would they ask us to achieve that? The answer is simple, really; search engines have the same problem as blind users. They cannot see the images.

Many webmasters and inexperienced or unethical SEOs abuse the use of this attribute, trying to stuff it with keywords, looking to achieve a certain keyword density, which isn't as relevant for rankings now as it was previously.

On the other hand, high keyword density can, on some search engines like google, trigger spam filters, which may result in a penalty for the site's ranking. Even without this type of penalty, your site's rankings will not take advantage of this tactic.
This process also puts persons who use screen readers at a greater disadvantage. Screen readers are software-based tools that really read aloud the contents of what is shown on the screen. In browsing the net, the alt features of images are read aloud too.

Imagine hearing a paragraph of text that is then repetitions of numerous keywords. The page would be far from accessible, and, to put it mildly, will be found quite annoying.
What exactly is an Alt attribute?

An ALT attribute shouldn't be used as a description or a label for an image, though many people utilize it for the reason that fashion. Although it may appear natural to assume that alternate text is really a label or a description, it is not!

The words used within an image's alt attribute ought to be its text equivalent and convey the same information or serve exactly the same purpose that the image would.

The thing is to provide the same functional information that a visual user would see. The alt attribute text should be the "stand in" when the look is not available. Ask yourself this: Should you replace the look using the text, would most users receive the same basic information, and wouldn't it generate the same response?
A few examples:

 

Some SEO Optimization Tips

If your search button is a magnifying glass or binoculars its alt text should be 'search' or 'find' not 'magnifying glass' or 'binoculars'.

If the image is supposed to convey the literal contents of the look, a description is appropriate.

If it is designed to convey data, then that information is what is appropriate.

If it is designed to convey using a function, then your function is what ought to be used.

Some Alt Attribute Guidelines:

Always add alt attributes to images. Alt is mandatory for accessibility as well as for valid XHTML.

For images that play only a decorative role within the page, make use of an empty alt (i.e. alt="") or perhaps a CSS background image to ensure that reading browsers don't bother users by uttering things like "spacer image".

Keep in mind that it is the function from the image we are attempting to convey. For example; any button images should not include the word "button" within the alt text. They should emphasize the action performed through the button.

Alt text ought to be determined by context. Exactly the same image in a different context may need drastically different alt text.

Try to flow alt text with the rest from the text because that is how it will be read with adaptive technologies like screen readers. Someone listening to your page should hardly remember that a graphic image can there be.
Please remember that utilizing an alt attribute for each image is needed to meet the minimum WAI requirements, that are used as the benchmark for accessibility laws in UK and the remainder of Europe. Also, they are required to meet "Section 508" accessibility requirements in america.

It is useful to categorize non-text content into three levels:

Eye-Candy
Mood-Setting
Content and Function

I. Eye-Candy

Eye-Candy are things that serve no purpose other than to create a site visually appealing/attractive and (oftentimes) fulfill the marketing departments. There is no content value (though there may be value to some sighted user).

Never alt-ify eye-candy unless there is something there that will boost the usability of the site for somebody using a non-visual user agent. Make use of a null alt attribute or background images in CSS for eye-candy.

II. Mood-Setting

This is the middle layer of graphics which might serve to set the mood or set the stage so to speak. These graphics are not direct content and may 't be considered essential, but they're important in they help frame what's going on.

Attempt to alt-ify the 2nd group as makes sense and is relevant. There may be times when doing this may be annoying or detrimental to other users. Then avoid it.

For instance; Alt text that is identical to adjacent text is unnecessary, as well as an irritant to screen reader users. I suggest alt="" or background CSS images in such instances. But sometimes, it's vital that you get this content in there for all users.

Usually this will depend on context. The same image in a different context may require drastically different alt text. Obviously, content ought to always be fully available. The way you use this case is really a judgment call.

III. Content and Function

This is where the image may be the actual content. Always alt-ify content and functional images. Title and long description attributes can also be in order.
The main reason many authors can't understand why their alt text isn't working is they don't know why the images are there. You have to determined precisely what function a picture serves. Think about what it is about the image that's vital that you the page's intended audience.

Every graphic includes a reason for being on that page: since it either improves the theme/ mood/ atmosphere or it is critical to what the page is trying to describe. Knowing what the look is for makes alt text simpler to write. And exercise writing them definitely helps.
A method to check the usefulness of alternative text would be to imagine reading the page over the telephone to someone. What would you say when encountering a specific image to make the page understandable to the listener?

Aside from the alt attribute you've got a couple more tools at your disposal for images.
First, in level of descriptiveness title is within between alt and longdesc. It adds useful information and can add flavor. The title attribute is optionally rendered through the user agent. Remember they're invisible and never shown as a "tooltip" when focus is received through the keyboard. (So much for device independence). So make use of the title attribute only for advisory information.
Second, the longdesc attribute points to the Link to a complete description of an image. If the information found in a picture is essential to the concept of the page (i.e. some important content will be lost if the image was removed), a longer description compared to "alt" attribute can reasonably display should be used. It can provide for rich, expressive documentation of the visual image.

It should be used when alt and title are insufficient to embody the visual qualities of an image. As Clark [1] states, "A longdesc is a long description of an image...The goal is to use any length of description necessary to impart the facts from the graphic.

It would not be remiss to hope that a long description conjures an image - the image - in the mind's eye, an analogy that holds true even for the totally blind."

Although the alt attribute is mandatory for web accessibility and for valid (X)HTML, not all images need alternative text, long descriptions, or titles.

Oftentimes, you are best just going with your gut instinct -- if it's not necessary to incorporate it, and when you don't have a strong urge to do it, don't include that longdesc.

However, if it's essential for the whole page to work, then you've to add the alt text (or title or longdesc).

What's necessary and what's not depends a lot about the function of your image and it is context about the page.

The same image may require alt text (or title or longdesc) in a single spot, but not in another. If the image provides simply no content or functional information alt="" or background CSS images may be appropriate to use. However, if the image provides content or adds functional information an alt would be required and perhaps a long description would be in order. Oftentimes this type of thing is a judgement call.

Image Seo optimization Tips


Listed below are key steps in optimizing images:

Select a logical file name that reinforces the keywords. You can use hyphens within the file name to isolate the keyword, but avoid to exceeding two hyphens. Avoid using underscores like a word separator, such as "brilliant-diamonds.jpg";

Label the file extension. For example, if the image search engine sees a ".jpg" (JPEG) file extension, it's going to assume that the file is a photo, and when it sees a ".gif" (GIF) file extension, it's going to assume that it is graphic;

Ensure that the written text nearby the image that's highly relevant to that image.
Again, do not lose an excellent chance to help your site together with your images in search engines. Begin using these steps to rank better on all of the engines and drive increased traffic to your site TODAY.

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