Friday, April 22, 2011

Alt Attribute & Search engine optimization

SEO Optimization images has become increasingly 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 the use of alternative text for that images on your web site:

Images:. Make use of the alt attribute to provide descriptive text. In addition, we recommend utilizing 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 have a similar problem as blind users. They can't see the images.

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

On the contrary, high keyword density can, on some search engines like google, trigger spam filters, which might result in a penalty for your site's ranking. Even without such a penalty, your site's rankings won't benefit from this plan.
This process 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 net, the alt features of images are read aloud as well.

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

An ALT attribute should not be used like a description or a label for an image, though lots of people utilize it for the reason that fashion. Though it might seem natural to assume that alternate text is really a label or a description, it's not!

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

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

 

Some SEO Optimization Tips

If a search button is really 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 contents of the look, then a description is appropriate.

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 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 within the page, use an empty alt (i.e. alt="") or perhaps a CSS background image so that reading browsers do not bother users by uttering such things as "spacer image".

Remember that it is the function from the image we are trying to convey. For example; any button images should not include the word "button" within the alt text. They should emphasize the action performed by the button.

Alt text ought to be based on context. The same image in 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 listening to your page should hardly be aware that a graphic image can there be.
Please remember that using an alt attribute for every image is needed to satisfy the minimum WAI requirements, that are used since the benchmark for accessibility laws in UK and also the remainder of Europe. Also, they are 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 stuff that serve no purpose apart from to create a site visually appealing/attractive and (in many cases) fulfill the marketing departments. There isn't any content value (though there may be value to some sighted user).

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

II. Mood-Setting

This is the middle layer of graphics which may actually set the mood or set happens as it were. These graphics aren't direct content and could 't 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 may 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 cases. But sometimes, it's vital that you get this content inside for all users.

Usually it depends on context. The same image in a different context may need drastically different alt text. Obviously, content ought to always be fully available. How you use 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 may also be in order.
The main reason many authors can't understand why their alt text isn't working is that they don't know why the images exist. You need to figured out precisely what function an image serves. Consider what it is about the image that's vital that you the page's intended audience.

Every graphic includes a reason behind being on that page: since 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 for makes alt text simpler to write. And exercise writing them definitely helps.
A way to look into the usefulness of alternative text would be to imagine reading the page over the telephone to someone. An amount you say when encountering a particular image to create 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 degree of descriptiveness title is in 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 not shown as a "tooltip" when focus is received via the keyboard. (A lot for device independence). So use the title attribute only for advisory information.
Second, the longdesc attribute points to the URL of a complete description of an image. When the information found in an image is essential to 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 may offer rich, expressive documentation of a 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 really a long description of an image...The aim is to use any period 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 look - in the mind's eye, an analogy that is true even for that 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 better off just going with your gut instinct -- if it's not necessary to include it, and if you don't have a strong urge to get it done, don't add that longdesc.

However, if it's necessary 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 its context about the page.

Exactly 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 make use of. However, if the image provides content or adds functional information an alt would be required and perhaps a long description will be in order. Oftentimes this kind of thing is really a judgement call.

Image Seo optimization Tips


Listed here are key steps in optimizing images:

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

Make sure that the text at the image that is highly relevant to that image.
Again, don't lose a great chance to help your site with your images in search engines. Begin using these steps to rank better on all of the engines and drive increased traffic for your site TODAY.

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