As CEO of Tesla and Space X, Elon Musk is leading two of the most innovative companies in the world. But even someone as smart and talented as Musk knows you don't innovate alone.

That's why a recent interview with Musk caught my attention. Speaking at the U.S. Air Force Space Pitch Day, Musk was asked how he and his companies find talent in the midst of strict competition, and Musk delivered an especially interesting sound bite:

"You want to make sure that...if somebody great wants to join the company that they actually get an interview. This is actually one of my big worries. Like, if Nikola Tesla was alive today, could he get an interview? And if not, we're doing something wrong. And I'm not totally sure he would get an interview. So, if one of the most brilliant engineers who ever lived could maybe not get an interview, we should fix that and make sure we're not barring the doors from talent, or that we're looking at the right things.

"Generally, look for things that are evidence of exceptional ability. I don't even care if somebody graduated from college or high school or whatever... Did they build some really impressive device? Win some really tough competition? Come up with some really great idea? Solve some really tough problem?"

Musk concluded the point with a remarkable question:

"What did they do that was clear evidence of exceptional ability?"

Five words that should be memorized by every hiring manager and recruiter, in every company:

Clear evidence of exceptional ability.

Musk's hiring rule is noteworthy because research indicates the correlation between education level and high performance on the job is weak. So much so that companies like Apple and Google no longer require employees to have four-year degrees.

So, what matters more than a degree? Intelligence, for one--along with emotional intelligence. The desire and ability to consistently learn and improve. And the hard skills needed to do the job at hand.

The more "exceptional ability" a candidate can demonstrate in these areas, the greater their potential to contribute to your company.

So, what does evidence of exceptional ability look like? And how can you make finding it part of your hiring practices?

It's easy to say "you'll know it when you see it," but the truth is that's not always the case. It's easy for recruiters and hiring managers to miss said evidence if they don't know how (or where) to look.

Here are three suggestions to help your organization identify clear evidence of exceptional ability in job candidates:

Ask them to solve a problem.

To help sift through your crop of candidates, pose a problem they'll need to solve. It could be a typical problem they'd be dealing with on any given day of the week (like how to deal with an irate customer). Or, it could be a more complex problem that your company is grappling with on a larger scale.

As you analyze candidates' answers, look for critical thinking skills, and the ability to clearly articulate thoughts and solutions.

Hold a contest.

A contest can be a great way to identify job candidates with potential to excel. 

For example, every year Microsoft hosts a hackathon during its One Week festival, which is part science fair and part tech expo. Employees are encouraged to bring their "world-changing ideas" to life. One Week is extremely popular among Microsoft employees, and has helped transform the company's reputation into a "cool employer."

Of course, your company's contest can focus on new hires. But Microsoft's hackathon is a perfect example of how to identify current employees with potential to advance. This is important for two reasons:

"This feels like, collectively, we're building toward more creativity," said one longtime Microsoft employee about the One Week hackathon. "It's why we're here."

Test for skills.

Rather than focus on what school someone went to or what type of degree they have, a handful of companies have discovered that exceptional talent comes from various backgrounds.

For example, a few years ago LinkedIn pioneered REACH, an engineering apprenticeship that gives opportunities to candidates "who are passionate about coding, have a strong interest in continuing to independently learn and grow, and are willing to put in the work to achieve their goals and better their community."

To be considered, applicants should expect to complete both an essay application and a coding challenge, to help recruiters determine their skill level.

What's not required from candidates? A college degree.

Of course, what qualifies as an ideal candidate will likely be different for your company than for others, and will also depend heavily on the position you're looking to fill. 

But great companies know that no position is permanent--and there's always room for great talent. So, if you're interested in hiring people who can help improve your company and move it forward, remember those five simple words:

Clear evidence of exceptional ability.