Dafaxetentcy: Alt Attribute & Search engine optimization

SEO Optimization images is becoming more and more essential in SEO (Seo optimization) for websites. The ALT attribute is a critical step that is sometimes forgotten. This is often a lost opportunity for better rankings.

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

Images:. Make use of the alt attribute to provide descriptive text. In addition, we recommend using a human-readable caption and descriptive text around the image.

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

Many webmasters and inexperienced or unethical SEOs abuse using this attribute, attempting to stuff it with keywords, hoping to achieve a particular keyword density, which is not as relevant for rankings now since it once was.

On the other hand, high keyword density can, on some search engines, trigger spam filters, which may create a penalty for your 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 at a greater disadvantage. Screen readers are software-based tools that actually read aloud the contents of what's shown on the screen. In browsing the web, the alt features of images are read aloud too.

Imagine hearing a paragraph of text which is followed by repetitions of many keywords. The page would be not even close to accessible, and, to put it mildly, would be found quite annoying.
What exactly is an Alt attribute?

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

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

The thing would be 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 question: If you were to replace the look with the text, would most users get the same basic information, and would it generate the same response?
Some examples:

Some SEO Optimization Tips

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

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

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

If it is meant to convey the use of a function, then the function is what should 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 in the page, use an empty alt (i.e. alt="") or perhaps a CSS background image to ensure that reading browsers do not bother users by uttering such things as "spacer image".

Keep in mind that it is the function of the image we're attempting to convey. For instance; any button images shouldn't range from the word "button" within the alt text. They ought to emphasize the action performed by the button.

Alt text ought to be determined by context. The same image inside a different context may require drastically different alt text.

Try to flow alt text with the rest from the text because that is how it is going to be read with adaptive technologies like screen readers. Someone hearing your page should hardly remember that a graphic image can there be.
Please remember that using an alt attribute for every image is required to satisfy the minimum WAI requirements, which are used as the benchmark for accessibility laws in UK and the rest of Europe. They are also required to meet "Section 508" accessibility requirements in the US.

It is important 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 make a site visually appealing/attractive and (oftentimes) fulfill the marketing departments. There isn't any content value (though there might be value to a sighted user).

Never alt-ify eye-candy unless there is something there that will enhance the usability from the site for someone 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 may actually set the mood or set happens as it were. These graphics are not direct content and may not be considered essential, but they're essential in that they help frame what is going on.

Attempt to alt-ify the 2nd group as is sensible and is relevant. There might be instances when doing this might be annoying or detrimental with other users. Then avoid it.

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

Usually it depends on context. The same image inside a different context may need drastically different alt text. Obviously, content should always be fully available. How you use this example is a judgment call.

III. Content and Function

This is when the image is the actual content. Always alt-ify content and functional images. Title and long description attributes may also be so as.
The reason many authors can't figure out why their alt text isn't working is they don't know why the images exist. You need to determined precisely what function a picture serves. Consider what it's concerning the image that's important to the page's intended audience.

Every graphic includes a reason behind being on that page: because it either enhances the theme/ mood/ atmosphere or it is advisable to what are the page is trying to explain. Knowing what the image is for makes alt text simpler to write. And practice writing them definitely helps.
A method to look into the usefulness of alternative text is to imagine reading the page on the phone to someone. An amount you say when encountering a specific image to make the page understandable to the listener?

Aside from the alt attribute you have a couple more tools available for images.
First, in degree 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 are invisible and not shown as a "tooltip" when focus is received through the keyboard. (A lot for device independence). So make use of the title attribute just for advisory information.
Second, the longdesc attribute points to the Link to a complete description of the image. If the information contained in a picture is important towards the concept of the page (i.e. some important content would be lost when the image was removed), a longer description than the "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 period of description necessary to impart the facts of the graphic.

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

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

Oftentimes, you're best just choosing your gut instinct -- if it's not essential to include it, and if you don't possess a strong urge to do it, don't include that longdesc.

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

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

The same image may need alt text (or title or longdesc) in one spot, but not in another. If an image provides absolutely no content or functional information alt="" or background CSS images might be appropriate to use. However, if the image provides content or adds functional information an alt will be required and perhaps a long description would be in order. In many cases this kind of thing is a judgement call.