Friday, April 22, 2011

Alt Attribute & SEO Optimization

SEO Optimization images has become increasingly more essential in SEO (Search Engine Optimization) for websites. The ALT attribute is a critical step that is often overlooked. This is often a lost chance of better rankings.


In Google's webmaster guidelines, they advise the use of alternative text for the images in your 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 achieve that? The answer is simple, really; search engines like google 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 certain keyword density, which is not as relevant for rankings now as it once was.

On the contrary, high keyword density can, on some search engines like google, trigger spam filters, which may 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 plan.
This process also puts persons who use screen readers at a greater disadvantage. Screen readers are software-based tools that actually read aloud the items in what's displayed on the screen. In browsing the web, the alt features of images are read aloud too.

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

An ALT attribute should not be used as a description or a label to have an image, though many people use it for the reason that fashion. Although it may appear natural to assume that alternate text is a label or perhaps a description, it's not!

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

The goal 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 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 would it generate the same response?
Some 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 the image is meant 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's meant to convey using a function, then your function itself 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 so that reading browsers don't bother users by uttering things like "spacer image".

Remember that it's the function of the image we are attempting to convey. For instance; any button images should not include the word "button" within the alt text. They should emphasize the action performed through the button.

Alt text should be based on context. The same image in a different context may need 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 remember 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 since the benchmark for accessibility laws in UK and the rest 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:

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 might be value to a sighted user).

Never alt-ify eye-candy unless there is 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 might serve to set the atmosphere or set happens so to speak. These graphics are not 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 is relevant. There may be instances when doing so might be annoying or detrimental to other users. Then avoid it.

For instance; 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 important to get this content in there for all users.

Most times this will depend on context. Exactly the same image in a different context may require drastically different alt text. Obviously, content ought to always be fully available. The way you use this case is a judgment call.

III. Content and Function

This is where 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 are there. You have to determined precisely what function an image serves. Think about what it's about the image that's vital that you the page's intended audience.

Every graphic includes a reason behind 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 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. What would you say when encountering a particular image to make the page understandable to the listener?

Besides the alt attribute you have a couple more tools available 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 make use of the title attribute just for advisory information.
Second, the longdesc attribute points towards the URL of a complete description of the image. If 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), an extended description than the "alt" attribute can reasonably display ought to be used. It may offer rich, expressive documentation of a 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 really a long description of the image...The aim is by using any period of description necessary to impart the details of the graphic.

It wouldn't be remiss to hope that the long description conjures an image - the image - within 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.

In many cases, you are best just choosing your gut instinct -- if it's not essential to incorporate it, and when 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 operate, 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 the image and it is context on the page.

Exactly the same image may need alt text (or title or longdesc) in a single spot, although not in another. If the image provides simply no content or functional information alt="" or background CSS images might 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 would be so as. In many cases this type of thing is a judgement call.

Image Search Engine Optimization Tips


Listed here are key steps in optimizing images:

Choose 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. Avoid using underscores like a word separator, such as "brilliant-diamonds.jpg";

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

Ensure that the text at the image that is highly relevant to that image.
Again, don't lose an excellent opportunity to help your website with your images searching engines. Use these steps to rank better on all the engines and drive more traffic for your site TODAY.

No comments:

Post a Comment