Performance review season has come into full swing, and the groans of business professionals can be heard across the country. While many employees dread performance reviews–yearly assessments of an employee’s quality of work–they are necessary and valuable for the modern workforce.

In fact, organizations that stopped doing performance reviews saw more negative results than positive, according to Brian Kropp, group vice president at Gartner. “For companies that have gotten rid of performance scores, people get really excited the first time that they don’t have to go through the process, because it’s time consuming and it can be frustrating,” Kropp said. “But by the time you get to the second time around, every bad thing that you can imagine happen starts to happen.”

SEE: Accomplishment tracker (Tech Pro Research)

When employees aren’t given the chance to receive feedback, then there isn’t an opportunity for problems to be addressed and solved, or for the employee themself to learn how they can improve. “It’s the same mindset as going to the dentist. Nobody enjoys going, but it’s really important that you go,” Kropp said.

Research has also shown that employees are more productive when they have goals, and they know how they’re performing against them, said Brian Westfall, Sr., an HR analyst at Capterra.

However, optimizing your performance review process is just as important as having these reviews instituted in the first place. If employees aren’t learning anything from their performance review and aren’t contributing anything to the review, then the experience is the same as not having on at all.

How employees can best prepare

Employees need to walk into performance reviews with as much detailed information about their work as possible, said Kropp.

“You almost have to go into it with the assumption that your manager or your boss doesn’t know what you’ve been working on,” Kropp said. “You would expect that your manager is really aware of what is going on and has been working with you across the course of the year, but that’s probably not true.”

The workplace dynamic has evolved in a way that often leaves managers in the dark when it comes to properly overseeing their employees, Kropp said. “As the world has gotten more complex, more matrixed, and more collaborative, most managers don’t actually have good insight to how their employees are spending their time,” he added.

Employees should focus on three major aspects of their performance during the meeting: Personal achievements, interactions with coworkers, and goals.

“For areas where you did really well, take notes on the specific things you did to achieve that success, and how you can share that wisdom with others,” said Westfall. “For areas where you did poorly, try to remember any external circumstances that could have affected your performance or, at the very least, figure out the steps you plan to take to improve in that area in the upcoming year.”

Employees should also prepare to talk about not only the impact they’ve had with their individual work, but how they’ve helped other people and made the overall team better, Kropp said.

Additionally, it’s important to make sure your goals and objectives have kept up with those of the company, and to show that to your supervisor, said Kropp. “If you haven’t kept up to date with the way that the business has been changing, then you’re probably still working on the stuff that was important a year ago, instead of what’s important now,” said Kropp. “There’s a recency bias that every manager has. You have to think through what your manager cares about now, and what can you tell your manager about what you’ve done in terms of impacting things that are happening now.”

SEE: Tips for getting the most from your performance reviews (free TechRepublic PDF)

How managers can best prepare

“As a manager, you’d like to think you know intuitively how your employees are performing, but that doesn’t always match the reality,” said Westfall. “Besides referencing employee performance metrics, managers should also leverage 360 feedback from that employee’s co-workers and other people they’ve worked with throughout the year–even clients or customers–to get a better picture of that employee’s true performance.”

Just as employees should prepare with the mindset that managers are unaware of their daily work, managers almost need to reflect with that same assumption. “A really hard question that you, as a manager, have to ask yourself is, do you really know what that person is working on?” said Kropp. “Because if you’re like most managers, the perceptions that you have are probably based on a limited number of interactions rather than the full picture.

“You, as a manager, have to rely less on your own personal experiences and more on getting feedback from that person’s peer,” Kropp added. “People in other business units, customers, direct reports. You have to really diversify all of the information that you get about an employee on your team to really understand the impact that any individual’s having.”