Friday, April 22, 2011

Alt Attribute & Search engine optimization

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


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

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

Why would they ask us to do that? The answer is simple, 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 the use of this attribute, trying to stuff it with keywords, looking 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 may result in a penalty for your site's ranking. Even without this type of penalty, your site's rankings will not benefit from this plan.
This method also puts persons who use screen readers in a greater disadvantage. Screen readers are software-based tools that really read aloud the items in what's shown on the screen. In browsing the web, the alt attributes of images are read aloud as well.

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

An ALT attribute should not be used like a description or perhaps a label to have an image, though lots of people use it in that fashion. Although it may appear natural to assume that alternate text is really a label or perhaps a description, it is not!

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

The thing is to supply the same functional information that a visual user would see. The alt attribute text should be the "stand in" in the event that the image is not available. Ask yourself this question: If you were to replace the image with the text, would most users receive the same basic information, and would it create 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 supposed to convey the literal items in the image, a description is suitable.

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

If it's designed to convey using 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, make use of an empty alt (i.e. alt="") or a CSS background image to ensure that reading browsers don't bother users by uttering such things as "spacer image".

Keep in mind that it is the function of the image we're trying to convey. For instance; 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 based on context. The same image in a different context may need drastically different alt text.

Try to flow alt text with the rest of 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 be aware that a graphic image is there.
Please keep in mind that using an alt attribute for each image is required to meet the minimum WAI requirements, which are used as the benchmark for accessibility laws in UK and also the rest of Europe. They are also necessary 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 create a site visually appealing/attractive and (in many cases) fulfill the marketing departments. There is no content value (though there might be value to a sighted user).

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

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

For example; Alt text that's identical to adjacent text is unnecessary, and 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 it depends on context. Exactly the same image inside a different context may require drastically different alt text. Obviously, content should always be fully available. The way you use this case is 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 main reason many authors can't figure out why their alt text isn't working is that they don't know why the pictures exist. You need to determined precisely what function a picture serves. Think about what it's about the image that's important to the page's intended audience.

Every graphic has a reason behind standing on that page: because it either improves the theme/ mood/ atmosphere or it is advisable to what are the page is trying to describe. Knowing what the image is perfect for makes alt text simpler to write. And exercise writing them definitely helps.
A way to look into the usefulness of alternative text is to imagine reading the page on the phone to someone. What would you say when encountering a particular 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 in between alt and longdesc. It adds useful information and can add flavor. The title attribute is optionally rendered by the user agent. Remember they're invisible and never shown like 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 towards the Link to a full description of the image. If the information contained in an image is important towards the concept of the page (i.e. some important content would be lost if the image was removed), an extended description than the "alt" attribute can reasonably display should be used. It may provide for rich, expressive documentation of a visual image.

It ought to 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 the image...The aim is to use any length of description essential to impart the facts of the graphic.

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

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

Oftentimes, you are best just choosing your gut instinct -- if it's not essential to incorporate it, and if you don't have a strong urge to do it, don't add that longdesc.

However, if it's necessary for the entire page to operate, then you've 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 its context about the page.

Exactly the same image may need alt text (or title or longdesc) in a single spot, although not in another. If an image provides absolutely no content or functional information alt="" or background CSS images might be appropriate to make use of. However, if the image provides content or adds functional information an alt will be required and perhaps a long description would be so as. Oftentimes this type of thing is a judgement call.

Image Search Engine Optimization Tips


Listed below are key stages in optimizing images:

Select a logical file name that reinforces the keywords. You can use hyphens in 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 instance, when the image search engine sees a ".jpg" (JPEG) file extension, it's likely to assume the file is a photo, and if it sees a ".gif" (GIF) file extension, it's likely to assume that it is a graphic;

Ensure that the written text at the image that's highly relevant to that image.
Again, do not lose an excellent opportunity to help your website with your images searching 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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