Dear Bob ...
I have a problem employee -- I'll call her "Angie" because I never liked Angie Dickinson, and I'm at the point where I can't stand "Angie" either.
[ Also on InfoWorld.com: Whether you're the employee or manager, it's never a good idea to point fingers at work, so stop blaming your predecessor for your company's problems. | Keep up on career advice with Bob Lewis's Advice Line newsletter. ]
It probably isn't her fault, either. I suspect she is ADHD and probably has Asperger's besides. She's clearly very smart, but she just can't stay focused on the task at hand. Instead, she's constantly making "helpful" suggestions -- to her coworkers, to me, to my peers, and even once to my boss (!).
While her attention is so strongly focused on how everyone else can improve, her own tasks don't get done on time. Often, when she does finish them, she hasn't done a particularly good job on them.
I'm hesistant to approach HR about this because I'm concerned it might turn into an ADA issue. But I can't continue with her the way things are, either.
- Coaching, unsuccessfully
Dear Coaching ...
First suggestion: Either change professions or stop psychoanalyzing. Your job is to lead, not to diagnose -- or at least not to diagnose in terms of disorders and syndromes. Every leader has to try to figure out what's driving employees, so as to do the best job possible of motivating and coaching them, but that isn't the same as attaching pop-psych buzzwords to them.
And from the sound of it, you're attaching the wrong pop-psych buzzwords. From what you describe, the right buzzword is "projection." It's what people do who take their own failings and instead of dealing with them, they see them in everyone else. My guess is that Angie is deeply unsure of her ability to succeed in her own role. Instead of getting her assignments finished -- where you, she, and everyone else would understand how her work stands up -- she takes on the much safer role of critic.
It really doesn't matter what's driving her. What matters is how you're coaching her. My opinion: What she needs to understand, and you have to help her understand, is that no matter how acute her observations might be regarding everyone else's performance, nobody will pay any attention to what she has to say unless they first respect her competence at her own work.