[uf-new] img alt content statistics

[Manu Sporny]

Manu Sporny wrote:
> As Scott has pointed out, the only way to know this is to start
> gathering real data. I am in the process of writing an image crawler
> (which will hopefully be done by tonight) to gather these statistics.

The first run of the img tag analysis has been completed, here are the
results:

Total websites crawled :  14077
Total img tags analyzed: 224671

The percentages below are the percentages of img tags that contained
non-empty attributes:

src:    99%
height: 66%
width:  66%
alt:    41%
title:   5%
id:      4%

In general, only 41% of 'img' tags list non-empty 'alt' attributes. In
other words - most websites are not using 'alt' attributes for 'img' tags.

The next step of the analysis process will examine how the sites that
ARE using 'alt' tags use them.

-- manu