Why do we spend so much time talking about goals as part of performance management? Every book, blog, and training program about improving employee performance starts with a conversation about goals. It’s become the most important tool for organizational and individual management, but why? What’s so great about a goal?

It turns out that goals work because that’s how our brains are wired. We can see how well it works using science! Here’s just one example. Tony Hsieh, CEO and chief happiness officer at Zappos, found that offering small promotions and title changes every three to six months instead of larger promotions every 12 to 18 months had a huge impact on productivity in his organization.

But it’s not enough to just have a goal. It turns out that our goal-planning process—how we go about setting goals—is just as important as having them in the first place. There was a lot of talk about a Yale study in 1953 that claimed that the 3 percent of graduates who had written goals accumulated more personal wealth than the 97 percent of their class that didn’t. The study turned out to be total fiction, but the underlying premise was so interesting that when scientists did an actual study of the effect of writing down goals, they found the impact to be substantial.

So we know that setting goals is a valuable exercise, and that writing them down and making them incremental make them more achievable. What else can science tell us about making our goal-planning process better?

In 2011 a group of scientists pulled together the results of a variety of smaller studies conducted over the years and found several other important factors related to the success of goal planning.

Specific goals are far more effective than vague goals.

For anyone who has ever been on a diet, this one is pretty obvious. If I say I want to lose weight, I’m much more likely to actually do it if I have a specific target of pounds to hit. This is why we so often hear about the SMART goal framework—specific goals allow us to measure success in a more meaningful way.

Stretch or difficult goals result in higher performance than setting the bar low.

People tend to rise to a challenge. Pushing yourself to do something hard means you blow right past those easy goals, and when you hit a stretch goal you feel as if you’ve really accomplished something.

Group-related goals are better for team performance than individually beneficial goals.

This one is a bit of a no-brainer: Having a goal that benefits the whole group will help the whole group perform better than a goal that only benefits one of the individuals. But the key message for managers is to be careful that goals within your team are aligned. Having two people working at cross purposes can make the whole team perform worse. 

Sometimes science tells us things we don’t expect, but in this case it looks like what we suspected all along is true: Good goals are good things, and writing them down makes it even more likely that we’ll achieve them! 

Three keys to success:

• Science backs up what managers have known for years—goals are a great way to improve performance.

• Specific is better than vague—make sure your goals are clear and well defined.

• Reach for the stars—stretch goals result in higher performance, so set the bar high.