savannah6st9: Alt Attribute & Search engine optimization

SEO Optimization images has become more and more important in SEO (Search Engine 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 using alternative text for the images in your 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 begin to 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 is not as relevant for rankings now since it was previously.

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

Imagine hearing a paragraph of text that is followed by repetitions of numerous keywords. The page would be far from accessible, and, to put it bluntly, will be found quite annoying.
What 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. Though it might seem natural to assume that alternate text is a label or perhaps a description, it's not!

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

The goal is to supply the same functional information that the visual user would see. The alt attribute text should function as a "stand in" in the event that the look is not available. Think about this question: 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 a search button is a magnifier 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 items in the look, a description is appropriate.

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

If it is meant to convey using a function, then your function itself is what should be used.

Some Alt Attribute Guidelines:

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

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

Remember that it is the function from the image we're 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 should be determined by context. Exactly the same image inside a different context may require drastically different alt text.

Attempt to flow alt text with the remainder from the text because that's the way 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 keep in mind that using an alt attribute for each image is needed to satisfy the minimum WAI requirements, which are used as the benchmark for accessibility laws in UK and also the remainder of Europe. They are also 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 stuff that serve no purpose apart from to make a site visually appealing/attractive and (in many cases) fulfill the marketing departments. There isn't any content value (though there might be value to some sighted user).

Never alt-ify eye-candy unless there's something there which will boost the usability from the site for somebody using a non-visual user agent. Use 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 atmosphere or set the stage so to speak. These graphics aren't direct content and may 't be considered essential, but they are essential in that they help frame what's going on.

Try to alt-ify the 2nd group as is sensible and it is relevant. There may be times when doing so may be annoying or detrimental with other users. Then try to avoid it.

For instance; Alt text that is just like 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 understand this content in there for those users.

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

III. Content and Function

This is where the look is the actual content. Always alt-ify content and functional images. Title and long description attributes can also be so as.
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 need to figured out exactly what function a picture serves. Consider what it is concerning the image that's important to the page's intended audience.

Every graphic has a reason for standing on that page: because it either enhances the theme/ mood/ atmosphere or it is advisable to what the page is trying to describe. Understanding what the look is for makes alt text simpler to write. And exercise writing them definitely helps.
A method to look into the usefulness of alternative text would be to imagine reading the page on the phone to someone. An amount you say when encountering a specific image to create the page understandable to the listener?

Besides the alt attribute you have a couple more tools at your disposal for images.
First, in level of descriptiveness title is in between alt and longdesc. It adds useful information and may 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. (So much for device independence). So use the title attribute just for advisory information.
Second, the longdesc attribute points to the Link to a full description of an image. When the information found 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 offer 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 a long description of an image...The aim is by using any length of description essential to impart the facts of 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 is true even for that totally blind."

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

In many cases, you are 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 get it done, don't add that longdesc.

However, if it's essential for the entire page to work, then you've to include 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 a single spot, although not in another. If the image provides absolutely no content or functional information alt="" or background CSS images may 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 will be in order. In many cases this kind of thing is a judgement call.