Summary of SEO principles on ALT attributes of images

Does the alt for a non-linked image is ignored by Google? If so, I will not trouble to optimize the alts for non-linked images on my page.
Thanks in advance.
Ethan
-Www.ihelpyouservices.com has a reply with Moderator. The content is as follows:
1, (M) Yes, that's true, at least right now. google only indexes the alt attribute of linked images. but that doesn't mean you shoshould leave the alt out of non-linked images. just use if for its real purpose: to describe the image for people who can't see it.
In the case of images that only serve the purpose of creating space, you can add an empty alt attribute (alt = "").
-Www.highrankings.com has two replies, one of which is Jill. Jill is one of the most famous SEO experts in the United States.
1, I think the general consensus is that engines ignore them but I 'd still put them in anyway-not optimised but for accessibility.
2, (Jill) Yes, you are correct, they are ignored by the search engines. Alt attributes aren't really an SEO technique, they are a design concern.
-Www.webproworld.com has 12 replies, two of which are replies from Moderator.
1, I doubt whether the image is linked matters. IMO the text will still count ...... probably not much though.
2, I 've heard that it doesn' t count at all, but it is text so I suppose that it counts a little. Most likely very little.
3, I 've heard it bounced around some other forums that Google will ignore alt text without a link. however, it is still a good idea to use them in case the image doesn't load, accessibility, etc; and the fact that Yahoo probably doesn't ignore them.
4, (M) Is there any proof that Google will ignore it if there is no link?
5. Google states in their guidelines to use proper web design methods to have good code in your pages. using an alt tag on images is something you do for accessibility, like achronister pointed out. site readers used by blind people scan the alt tags and the speaker reads the text to them so blind people know what the images are there. it's just a good practice to get in.