F13 is ambiguous as for what causes which SC to fail

[baldino-m]

The Technique F13 fails 1.1.1 and 1.4.1 SC since the alternative text of the image makes references to the colour of the bars (bar chart). Please note that:

• inside the description, it is stated that this improper alternative text "can cause problems for people who are blind, have low vision, or have color vision deficiency" and this is, in my opinion, not totally appropriate, since alternative texts are intended for screen reader users mainly (probably there are cases of low vision screen reader users, but I doubt that people with colour deficiency use such a technology);
• it is not clear that, even if the text alternative is to be fixed, the image will still fail SC 1.4.1 (although the image is not provided, given the way it is described, it seems to fail SC 1.4.1, since it is suggested that the colour of the bars is the only way to provide information). It is not clear that this is a very specific example which fails both 1.1.1 and 1.4.1 SC (and SC 1.3.3? More on that later) at the same time and, fixing the alternative text, only the 1.1.1 (and 1.3.3) bit is fixed;
• it seems to me that, since the alternative text of an image is not visual information, the example also fails SC 1.3.3 (given that the image also fails SC 1.4.1 given its visual appearance). As per my understanding, SC 1.4.1 is specific for sighted users only.

Given the above:

• a bar chart image is to be provided, or its appearance described in detail, in order to decide if its visual appearance fails SC 1.4.1;
• if the intent of the technique is to focus on the alternative text only and the image is not relevant, then this fails SC 1.1.1 and 1.3.3. The fact that it still fails 1.4.1 is to be made clear with a note.