Today is National Boss's Day -- do you know where your boss is?

We all know what it's like to work for a bad boss -- it can be an incredibly frustrating experience. In fact, researchers have found that over 35 percent of professionals have quit their job because of a manager, and 15 percent of professionals are considering quitting their job because of their manager.

Bad bosses aren't an illusion -- they really do exist. If you're a boss, are you a good one? How do you know?

LinkedIn Learning just released the results of a survey of almost 3,000 professionals, asking them this question: What is the single most frustrating trait you have experienced in a manager?

Here are the top-four traits of bad bosses revealed by the survey:

1. Having expectations that aren't clear or that frequently change (20%)

2. Micromanaging (12%)

3. Being aloof and not involved (11%)

4. Not fostering professional development (11%)

Regarding the #1 bad boss trait above, leadership training expert Elizabeth McLeod says,

"A lack of clear expectations is the root cause of poor performance. Leaders often think they're clear, but the data tells us a different story. Employees need to know why this matters (the purpose) and what good looks like (performance expectations). Show me a leader who says, 'I shouldn't have to tell them, it should be obvious,' and we'll show you a team that isn't clear."

Need help (or have a boss who needs help)? LinkedIn has unlocked four LinkedIn Learning courses until December 31st, focused on each of these problem areas:

1. Setting Clear Expectations: Leading with Vision

2. How to Not Micromanage: Delegating Tasks

3. Staying Connected to Your Employees: Ken Blanchard on Servant Leadership

4. Fostering Your Development: Coaching Skills for Leaders and Managers

The price is right (free), so why not give them a try? The best boss is a great boss, and these courses can help get anyone on the right path.