Friday, April 22, 2011

Alt Attribute & SEO Optimization

SEO Optimization images is becoming more and more essential in SEO (Search Engine Optimization) for websites. The ALT attribute is a critical step that is often overlooked. This is often a lost opportunity for better rankings.


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

Images:. Make use of 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 easy, really; search engines like google have a similar problem as blind users. They cannot begin to see the images.

Many webmasters and inexperienced or unethical SEOs abuse using this attribute, trying to stuff it with keywords, hoping to achieve a particular keyword density, which isn't as relevant for rankings now since it was previously.

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

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

An ALT attribute shouldn't be used like a description or a label for an image, though lots of people use it in that fashion. Although it might seem natural to assume that alternate text is really a label or a description, it's not!

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

The goal 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 unavailable. Ask yourself this: Should you replace the image using the text, would most users receive the same basic information, and wouldn't it generate the same response?
Some examples:

 

Some SEO Optimization Tips

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

If the image is meant to convey the literal contents of the look, a description is suitable.

If it's meant to convey data, then that data is what is appropriate.

If it's meant to convey using a function, then the function itself 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 merely a decorative role in 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 such things as "spacer image".

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

Alt text should be determined by context. Exactly the same image in a different context may require drastically different alt text.

Try to flow alt text with the rest of the text because that's the way it will be read with adaptive technologies like screen readers. Someone listening to your page should hardly remember that a graphic image is there.
Please keep in mind that using an alt attribute for each image is needed to satisfy the minimum WAI requirements, that are used since the benchmark for accessibility laws in UK and the rest of Europe. Also, they are required to meet "Section 508" accessibility requirements in the US.

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 might be value to some sighted user).

Never alt-ify eye-candy unless there's something there which will enhance the usability from the site for somebody utilizing 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 actually the middle layer of graphics which might actually set the mood or set happens as it were. These graphics aren't direct content and could not be considered essential, but they are important in that they help frame what is going on.

Try to alt-ify the second group as makes sense and it is relevant. There may be times when doing so may be annoying or detrimental to other users. Then try to avoid it.

For example; Alt text that's just like adjacent text is unnecessary, and an irritant to screen reader users. I recommend alt="" or background CSS images in such cases. But sometimes, it's important to get this content in there for those users.

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

III. Content and Function

This is when the look may be the actual content. Always alt-ify content and functional images. Title and long description attributes can also be so as.
The reason many authors can't understand why their alt text isn't working is that they don't know why the pictures exist. You need to figured out precisely what function a picture serves. Think about what it's concerning 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 explain. Understanding what the look is perfect for makes alt text easier to write. And exercise writing them definitely helps.
A method to check the usefulness of alternative text is to imagine reading the page over the telephone to someone. What would you say when encountering a particular image to make the page understandable towards the listener?

Aside from the alt attribute you have a couple more tools available for images.
First, in level of descriptiveness title is within between alt and longdesc. It adds useful information and may add flavor. The title attribute is optionally rendered by the user agent. Remember they're invisible and not shown like a "tooltip" when focus is received through the keyboard. (So much for device independence). So use the title attribute only for advisory information.
Second, the longdesc attribute points towards the Link to a complete description of an image. When the information contained in an image is important towards the meaning of the page (i.e. some important content would be lost if the image was removed), an extended description compared to "alt" attribute can reasonably display should be used. It can provide for rich, expressive documentation of a visual image.

It should be used when alt and title are insufficient to embody the visual qualities of the image. As Clark [1] states, "A longdesc is really a long description of the image...The goal is by using any length of description essential to impart the details of the graphic.

It wouldn't be remiss to hope that a long description conjures a picture - the look - within the mind's eye, an analogy that is true even for the totally blind."

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

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

However, if it's necessary for the entire page to operate, then you've to include the alt text (or title or longdesc).

What's necessary and what's not depends a lot on 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 an image provides simply no content or functional information alt="" or background CSS images might be appropriate to make use of. But if the image provides content or adds functional information an alt will be required and maybe a long description would be in order. In many cases this kind 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 should use hyphens in the file name to isolate the keyword, but avoid to exceeding two hyphens. Stay away from underscores like a word separator, such as "brilliant-diamonds.jpg";

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

Ensure that the text nearby the image that's relevant to that image.
Again, don't lose an excellent chance to help your website with your images in search engines. Begin using these steps to rank better on all of the engines and drive more traffic to your site TODAY.

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