you can also rule out anyone who isn’t running Javascript, including a large chunk of people using assistive technology
We need to keep in mind here that, if “assistive technology” means screen readers, screen magnifiers and speech-control programs like Dragon Naturally Speaking, then Javascript is enabled for a majority of those people (for the same reasons it’s enabled for the majority of any random web user: it’s on by default in the browser and most people are not behind a script-blocking firewall or some such).
The group of disabled who will have Javascript turned off are the people with things like photosensitive epilepsy, balance problems, extreme motion sickness and possibly people with attention disorders (because Javascript is often used to create distractions and goofy animations on pages than real direct basic functionality). If the site fights them that much, they’ll leave.
Mailto links are retarded, and don’t work on my machine (after Evolution did a final, spectacular crash, I removed it from my computer entirely… what a worthless steaming pile of code that is), I highlight the link and copy it, and paste into my mail editor. Problem solved. I do hate accidentally clicking on the things though. Annoying.
In the absence of supporting data,
I don’t think you’ll ever get good data on that… even Yahoo’s “test” was seriously flawed, but in general most analytics on web sites are performed by… you guessed it, Javascript. And tests like the one Yahoo did are too stupid to account for users whose Javascript is disabled via firewalls and plugins rather than in the browser itself. Almost every browser comes with a Javascript parser and such browsers have it enabled by default.
In my experience the number of users with javascript disabled or using assistive technology is relatively tiny.
The number of users with Javascript disabled is probably tiny. The number using assisitive technology, you cannot know, for they are not measurable via analytics in any way, shape or form (well, unless you want to add a survey to your site… but then, most people don’t bother answering surveys which is why they are unreliable in representing all your users). You cannot detect if someone is using a screen reader or other application on their computer on top of their browser. Which is disappointing, for we’d all love to know the stats on these folks.