Friday, April 22, 2011

Alt Attribute & Search engine optimization

SEO Optimization images has become increasingly more important in SEO (Seo optimization) for websites. The ALT attribute is really a critical step that is often overlooked. This can be a lost opportunity for better rankings.


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

Images:. Use the alt attribute to supply descriptive text. Additionally, we recommend utilizing 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 the same problem as blind users. They can't 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 isn't as relevant for rankings now as it once was.

On the other hand, high keyword density can, on some search engines, 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 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 attributes of images are read aloud as well.

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

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

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

The goal is to provide the same functional information that a visual user would see. The alt attribute text should function as a "stand in" when the look is not available. Ask yourself this question: If you were to replace the look with 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 magnifying glass 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 suitable.

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

If it is designed to convey using 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 and for valid XHTML.

For images that play merely a decorative role within the page, use an empty alt (i.e. alt="") or perhaps a CSS background image to ensure that reading browsers do not bother users by uttering such things as "spacer image".

Keep in mind that it's the function from the image we're attempting to convey. For instance; any button images shouldn't range from the word "button" within the alt text. They should emphasize the action performed by the button.

Alt text ought to be based on 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 how it will be read with adaptive technologies like screen readers. Someone hearing your page should hardly be aware that a graphic image is there.
Please remember that using an alt attribute for each image is needed to satisfy the minimum WAI requirements, which are used since the benchmark for accessibility laws in UK and the remainder 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 stuff that serve no purpose apart from to make a site visually appealing/attractive and (in many cases) 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 from the site for somebody 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 serve to set the atmosphere or set the stage as it were. These graphics aren't direct content and could not be considered essential, but they are essential in that they help frame what's going on.

Try to alt-ify the 2nd group as is sensible and it is relevant. There may be times when doing this might be annoying or detrimental with other users. Then try to avoid it.

For instance; Alt text that's identical to 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 important to get this content inside for all users.

Usually it depends on context. The same image inside a different context may require drastically different alt text. Obviously, content ought to always be fully available. How you use this example is really 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 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 images exist. You need to determined precisely what function a picture serves. Think about what it is concerning the image that's vital that you the page's intended audience.

Every graphic has a reason behind being on that page: because it either improves the theme/ mood/ atmosphere or it is advisable to what are the page is attempting to describe. Understanding what the image is perfect for makes alt text easier 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 on the phone to someone. An amount you say when encountering a particular image to make the page understandable to the listener?

Besides the alt attribute you've got a couple more tools available 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 not shown as a "tooltip" when focus is received via 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 URL of a full description of the image. When the information found in a picture is important to the meaning of the page (i.e. some important content would be lost when the image was removed), an extended description compared to "alt" attribute can reasonably display ought to be used. It can provide for rich, expressive documentation of the 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 goal is to use any period of description necessary to impart the details of the graphic.

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

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

Oftentimes, you are better off just choosing your gut instinct -- if it's not essential to include it, and if you don't possess a strong urge to do it, don't include that longdesc.

However, if it's essential for the entire page to work, 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 your image and its context on the page.

Exactly 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 would be required and maybe 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 steps in optimizing images:

Select a logical file name that reinforces the keywords. You should use hyphens within 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, when the image internet search engine sees a ".jpg" (JPEG) file extension, it's going to assume that the file is really a photo, and if 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's highly relevant to that image.
Again, don't lose a great opportunity to help your website with your images in search engines. Begin using these steps to position better on all of the engines and drive more traffic for your site TODAY.

No comments:

Post a Comment