Friday, April 22, 2011

Alt Attribute & Seo

SEO Optimization images has become more and more essential in SEO (Seo optimization) for websites. The ALT attribute is really 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 round the image.

Why would they ask us to do that? The answer is simple, really; search engines 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, hoping to achieve a particular keyword density, which is not as relevant for rankings now as it was previously.

On the contrary, high keyword density can, on some search engines like google, 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 really read aloud the contents of what's displayed on the screen. In browsing the net, the alt features of images are read aloud too.

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

An ALT attribute shouldn't be used like a description or perhaps a label to have an image, though many people utilize it in that fashion. Though it might seem natural to assume that alternate text is a label or a description, it's not!

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

The thing 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: Should you replace the look with 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 magnifier or binoculars its alt text should 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's meant to convey data, then that information is what is appropriate.

If it is designed to convey the use of a function, then the function 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, use an empty alt (i.e. alt="") or a CSS background image to ensure that reading browsers do not bother users by uttering things like "spacer image".

Keep in mind that it is the function of the image we are trying to convey. For example; any button images shouldn't range from the word "button" within the alt text. They should emphasize the action performed through the button.

Alt text ought to be based on context. Exactly the same image in a different context may require drastically different alt text.

Attempt to flow alt text with the rest of the text because that's how 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 needed to satisfy the minimum WAI requirements, which are used as 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 other than to create a site visually appealing/attractive and (in many cases) satisfy the marketing departments. There is no content value (though there may be value to some sighted user).

Never alt-ify eye-candy unless there's something there that will boost the usability of 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 may actually set the mood or set happens as it were. These graphics are not direct content and could not be considered essential, but they are important in that they help frame what's going on.

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

For example; Alt text that's identical to adjacent text is unnecessary, as well as an irritant to screen reader users. I suggest alt="" or background CSS images in such cases. But sometimes, it's vital that you understand 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 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 in order.
The main reason many authors can't understand why their alt text isn't working is they don't know why the pictures exist. You need to determined precisely what function a picture serves. Think about 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 critical to what the page is attempting to describe. Knowing what the look is perfect for makes alt text easier to write. And exercise writing them definitely helps.
A way to check 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 make the page understandable towards 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 within 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 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 to the Link to a complete description of the image. If the information contained in a picture is important to the meaning of the page (i.e. some important content will 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 the visual image.

It ought to 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 by using any period of description essential to impart the details of the graphic.

It would not be remiss to hope that the long description conjures an image - the look - within the mind's eye, an analogy that is 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 get it done, 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 lot about the function of the image and its context about the page.

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

Image Seo optimization Tips


Listed below are key stages in optimizing images:

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

Ensure that the text at the image that's highly relevant to that image.
Again, don't lose an excellent opportunity to help your site together with your images in search engines. Use these steps to rank better on all the engines and drive increased traffic to your site TODAY.

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