Friday, April 22, 2011

Alt Attribute & SEO Optimization

SEO Optimization images is becoming increasingly more essential in SEO (Search Engine Optimization) for websites. The ALT attribute is a critical step that is often overlooked. This can be a lost opportunity for better rankings.


In Google's webmaster guidelines, they advise using alternative text for that 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 do that? The answer is simple, really; search engines have the same problem as blind users. They can't begin to see the images.

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

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 such a penalty, your site's rankings will not take advantage of 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 is shown on the screen. In browsing the web, the alt features of images are read aloud as well.

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

An ALT attribute shouldn't be used as a description or a label to have an image, though lots of people use it for the reason that fashion. Although it might seem natural to assume that alternate text is really a label or a description, it's not!

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

The goal is to provide the same functional information that the visual user would see. The alt attribute text should be the "stand in" in the event that the image itself is not available. Think about this: If you were to replace the image 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 a search button is a magnifier or binoculars its alt text ought to be 'search' or 'find' not 'magnifying glass' or 'binoculars'.

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

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

If it's meant to convey the use of 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, 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".

Remember that it is the function of the image we're trying to convey. For instance; any button images shouldn't include the word "button" in the alt text. They ought to emphasize the action performed through the button.

Alt text ought to be determined by context. Exactly the same image in a different context may need drastically different alt text.

Try to flow alt text with the rest from the text because that is 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 every image is needed to meet the minimum WAI requirements, which are used since the benchmark for accessibility laws in UK and the rest 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 things that serve no purpose other than to make a site visually appealing/attractive and (oftentimes) fulfill the marketing departments. There is no content value (though there may be value to a sighted user).

Never alt-ify eye-candy unless there's something there that 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 the middle layer of graphics which might actually set the atmosphere or set the stage so to speak. These graphics aren't direct content and may not be considered essential, but they are essential in they help frame what is going on.

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

For example; Alt text that's just like adjacent text is unnecessary, as well as an irritant to screen reader users. I recommend alt="" or background CSS images in such instances. But sometimes, it's vital that you get this content inside 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 where the image 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 pictures exist. You have to determined exactly what function an image serves. Consider what it is concerning the image that's vital that you the page's intended audience.

Every graphic includes a reason for being on that page: since it either enhances the theme/ mood/ atmosphere or it is advisable to what the page is trying to explain. Knowing what the look is perfect for makes alt text easier to write. And exercise writing them definitely helps.
A method to check the usefulness of alternative text is to imagine reading the page on the phone to someone. An amount you say when encountering a particular image to create 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 can add flavor. The title attribute is optionally rendered through the user agent. Remember they are invisible and never shown as a "tooltip" when focus is received via the keyboard. (A lot for device independence). So use the title attribute just for advisory information.
Second, the longdesc attribute points to the URL of a full description of the image. When the information contained in a picture is important to the concept of the page (i.e. some important content will be lost if the image was removed), an extended description compared to "alt" attribute can reasonably display should be used. It can provide for rich, expressive documentation of the 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 an image...The aim is by using any length of description necessary to impart the facts from the graphic.

It would not be remiss to hope that a long description conjures a picture - 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 and for valid (X)HTML, not all images need alternative text, long descriptions, or titles.

Oftentimes, you are best just going with your gut instinct -- if it's not essential to include it, and if you don't have a strong urge to get it done, don't include that longdesc.

However, if it's essential for the entire page to work, then you've to add the alt text (or title or longdesc).

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

The same image may require alt text (or title or longdesc) in one spot, although not in another. If the 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 so as. Oftentimes this type of thing is a judgement call.

Image Seo optimization Tips


Listed below are key steps 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. Stay away from underscores like a word separator, like for example "brilliant-diamonds.jpg";

Label the file extension. For instance, if the image internet search engine sees a ".jpg" (JPEG) file extension, it's going 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;

Make sure that the written text at the image that is relevant to that image.
Again, do not lose a great opportunity to help your site together with your images in search engines. Begin using these steps to rank better on all of the engines and drive more traffic to your site TODAY.

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