Earlier quoted context omitted.
Shakiness affects many of us as we get older, but it is hard to design a website around this constraint. Is it? Large link targets surrounded by empty negative space seem like an easy way to solve this problem. The issue is only an issue because Yahoo puts the links in tinytext and crowds the ad link right up next to the "Inbox" link, so a twitch can send the cursor scooting past the link you want to click on to the…
In the example provided the ad link has a decent amount of white space between it and the inbox link. There's even an intended barrier between the two in the form of a horizontal rule, granted one pixel. What more do you want? Are we to ascertain the shakiness level of the user to determine the proper amount of white space? A CSS media query maybe? @media min-shakiness: 0.5 and max-shakiness: 1 But then, I'm just bei…
See, you've misunderstood the root of the problem. This person knew exactly where he wanted to click, he aimed for those targets, and his physical limitations caused him to miss those targets. User intent is not the problem.
The problem here is the penalty for missing: he gets shuttled to an off-site advertisement that doesn't have anything to do the task at hand. If he misses and just goes to Drafts instead of Inbox, that's a much easier mistake for the user to understand and correct; the intended target link is still prominent on the unintended page, it's easy to connect cause with effect ("Stupid shaky hand, oops!"), and it's easy to try again. Unfortunately, in this case, that advertisement's placement makes it a very expensive miss for the user. Before the user even knows what has happened, he's on another site entirely. And that ad is placed between what are arguably the two most important links in the interface: Inbox and Compose.
In the example provided the ad link has a decent amount of white space between it and the inbox link. There's even an intended barrier between the two in the form of a horizontal rule, granted one pixel. What more do you want?
He probably missed the targets because they're skinny and/or long and require a good deal of "vertical accuracy", which can easily devolve into "vertical inaccuracy". The targets should be given some additional vertical size. This is anecdotal based upon experiences with my own shaky hand, so YMMV.