Does a user’s experience decrease in quality when they are using a screen reader or text browser to view a site that fails to put full alternate tags on the images?

This is a question that I ask frequently when I am talking to people in the accessibility world. For instance, the image on the front page of my blog has an alt tag that states: “the author riding on a boat at sunset”.

Is this something that adds to the user’s experience if they aren’t viewing the image?

I think it depends on the content of the site. For instance on a blog like this, a visitor might want to get an idea of what types of images the author puts on their site. Since it is a personal site, knowing more about the person is important.

Alternatively, on a shopping site I don’t think it is necessary. For instance, on a grocery site the text should state bananas, so the alt text does not also need to state “bananas” – it could instead state ” “. Allowing the user to not have to listen or read that extraneous information.

On a news site it might be helpful to know that there were images of a person at the scene of a crime, or of a building burning. It would give the user information about the disposition of the article, and would allow sighted users to make a decision whether they wanted to view the image at a later date.

What are your thoughts and practices with regard to this issue?