Friday, April 22, 2011

Alt Attribute & SEO Optimization

SEO Optimization images has become more and more important in SEO (Seo optimization) for websites. The ALT attribute is really a critical step that is often overlooked. 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:. 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 easy, really; search engines have a similar 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, hoping 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, trigger spam filters, which might result in a penalty for the site's ranking. Even without this type of penalty, your site's rankings won't take advantage of this tactic.
This method also puts persons who use screen readers in a greater disadvantage. Screen readers are software-based tools that actually read aloud the items in what is 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 which is then repetitions of many 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 a label to have an image, though lots of people utilize it for the reason that fashion. Though it may appear natural to assume that alternate text is a label or perhaps a description, it is not!

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

The thing would be to provide 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 itself is unavailable. Ask yourself this: Should you replace the look 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 your search button is a magnifier or binoculars its alt text should be 'search' or 'find' not 'magnifying glass' or 'binoculars'.

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

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

If it is meant to convey the use of a function, then your function is what ought to 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 only a decorative role in the page, use an empty alt (i.e. alt="") or a CSS background image so 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 attempting to convey. For example; any button images should not include the word "button" in the alt text. They should emphasize the action performed through the button.

Alt text should be determined by context. The same image inside a different context may require drastically different alt text.

Try to flow alt text with the remainder of 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 each image is required to meet the minimum WAI requirements, that are used as the benchmark for accessibility laws in UK and the remainder of Europe. Also, they are required to meet "Section 508" accessibility requirements in america.

It is useful to categorize non-text content into three levels:

Content and Function

I. Eye-Candy

Eye-Candy are things that serve no purpose other than to create a site visually appealing/attractive and (oftentimes) 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 that will enhance the usability of the site for someone 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 the middle layer of graphics which might serve to set the atmosphere or set happens so to speak. These graphics are not direct content and could not be considered essential, but they're important in they help frame what's going on.

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

For instance; Alt text that is identical to adjacent text is unnecessary, and an irritant to screen reader users. I recommend alt="" or background CSS images in such cases. But sometimes, it's vital that you get this content inside for those users.

Usually this will depend on context. Exactly the same image inside a different context may need drastically different alt text. Obviously, content ought to always be fully available. The way you go in this example is a judgment call.

III. Content and Function

This is when the look is 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 that they don't know why the pictures are there. You need to figured out exactly 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 being on that page: because it either enhances the theme/ mood/ atmosphere or it is advisable to what are the page is trying to describe. Understanding what the look is perfect for makes alt text easier to write. And practice 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. What would 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 degree 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 not shown as a "tooltip" when focus is received via the keyboard. (A lot for device independence). So make use of the title attribute only for advisory information.
Second, the longdesc attribute points towards the URL of a full description of an image. If the information found in a picture 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 ought to be used. It may 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 a long description of the image...The goal is by using any period of description essential to impart the details of the graphic.

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

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

However, if it's necessary for the entire page to operate, 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 the image and its context on the page.

The same image may need alt text (or title or longdesc) in one spot, but not in another. If an 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 will be required and perhaps a long description will be in order. Oftentimes this type of thing is really a judgement call.

Image Search Engine Optimization Tips

Listed here 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. Avoid using underscores like a word separator, like for example "brilliant-diamonds.jpg";

Label the file extension. For instance, when the image internet search engine sees a ".jpg" (JPEG) file extension, it's likely to assume that the file is a photo, and if it sees a ".gif" (GIF) file extension, it's likely to assume that it is graphic;

Ensure that the text nearby the image that is highly relevant to that image.
Again, do not lose an excellent chance to help your site together with your images in search engines. Use these steps to position better on all of the engines and drive more traffic for your site TODAY.

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