What are check-ins for?
Objectives are set by an employee with or without the help of their manager. Check-ins are the process by which those objectives are updated to show progress.
For instance, if your Key Result on an objective is to produce 100 widgets, you would do a weekly check-in and update that number. Perhaps 11 the first week and then a total of 23 the following week. This way, you and your manager are up to date and can track progress across your various objectives easily.
How to check-in
Go to Performance > Objectives > Personal and then click Check In under the objective you want to check-in for.
This will take you to a simple screen as shown below where you can update the values of your various Key Results. You'll also be able to indicate whether YOU think the Key Result is Off Track, On Track or Needs Attention.
Completing (or not completing) Objectives
Finally, you'll be able to mark the objective as complete or incomplete. If you've hit the targets, mark the objective as complete. If not and you're going to abandon progress on the objective, mark it as incomplete. This will preserve the data associated with the objective for future performance evaluations but hide it from your personal screen.