Hi-Tech Industry: Alt Attribute & SEO Optimization

SEO Optimization images is becoming increasingly more important in SEO (Search Engine Optimization) for websites. The ALT attribute is a critical step that is sometimes forgotten. This can be a lost chance of 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 supply descriptive text. In addition, we recommend utilizing a human-readable caption and descriptive text round the image.

Why would they ask us to do that? The answer is easy, really; search engines like google have a similar problem as blind users. They cannot see the images.

Many webmasters and inexperienced or unethical SEOs abuse using this attribute, trying to stuff it with keywords, hoping to achieve a particular keyword density, which isn't as relevant for rankings now since it once was.

On the contrary, high keyword density can, on some search engines like google, trigger spam filters, which may create a penalty for the site's ranking. Even without such a penalty, your site's rankings won't 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 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 that is then repetitions of many keywords. The page will be not even close to accessible, and, to put it mildly, would be found quite annoying.
What exactly is an Alt attribute?

An ALT attribute should not be used like a description or 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 really a label or a description, it is not!

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

The thing would be 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 image is unavailable. Ask yourself this question: Should you replace the image with the text, would most users get the same basic information, and wouldn't it create the same response?
Some examples:

Some SEO Optimization Tips

If a search button is a magnifying glass or binoculars its alt text should be 'search' or 'find' not 'magnifying glass' or 'binoculars'.

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

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

If it's designed to convey using a function, then your 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 in 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 attempting to convey. For instance; any button images should not range from the word "button" within the alt text. They should emphasize the action performed through the button.

Alt text should be based on context. Exactly the same image in a different context may need drastically different alt text.

Attempt to flow alt text with the remainder of the text because that's the way it will be read with adaptive technologies like screen readers. Someone listening to your page should hardly remember that a graphic image can there be.
Please remember that utilizing an alt attribute for every image is needed to satisfy the minimum WAI requirements, which are used as the benchmark for accessibility laws in UK and the rest of Europe. They are also necessary 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 create a site visually appealing/attractive and (in many cases) satisfy the marketing departments. There isn't any content value (though there might be value to some sighted user).

Never alt-ify eye-candy unless there is something there that will boost the usability of the site for somebody 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 actually the middle layer of graphics which might actually set the mood or set happens as it were. These graphics aren't direct content and could 't be considered essential, but they are important in they help frame what is going on.

Try to alt-ify the second group as is sensible and it is relevant. There might be instances when doing this might be annoying or detrimental with 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 suggest alt="" or background CSS images in such instances. But sometimes, it's vital that you understand this content in there for all users.

Usually it depends on context. Exactly the same image in 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 may be the actual content. Always alt-ify content and functional images. Title and long description attributes may also be in order.
The reason many authors can't figure out why their alt text isn't working is they don't know why the images exist. You have to determined exactly what function a picture serves. Think about what it is about the image that's important to the page's intended audience.

Every graphic has a reason for standing on that page: because it either improves the theme/ mood/ atmosphere or it is advisable to what are the page is trying to explain. Knowing what the look is for makes alt text easier to write. And exercise writing them definitely helps.
A method to check 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 create the page understandable towards the listener?

Besides the alt attribute you've got a couple more tools available for images.
First, in degree 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 never shown like 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 the image. When the information contained in a picture is essential to the concept of the page (i.e. some important content will be lost if the image was removed), an extended description than the "alt" attribute can reasonably display should 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 aim is by using any period of description necessary to impart the details from the graphic.

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

Even though 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 going with your gut instinct -- if it's not essential to incorporate it, and when you don't possess a strong urge to do it, don't include that longdesc.

However, if it's necessary for the whole page to operate, then you have to include the alt text (or title or longdesc).

What's necessary and what's not depends a lot on the function of the image and its context on the page.

The same image may need alt text (or title or longdesc) in a single spot, although 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 perhaps a long description would be so as. Oftentimes this type of thing is a judgement call.