If you have upgraded your free Quizlet account to Quizlet Teacher, you will have access to aggregate class progress on sets that you create. You can see which terms your students need the most help with and direct your in-class teaching to focus more on the hard terms or concepts. You can also see who has studied your set.
You can access this view from any set that you have created via the "Class Progress" tab. This tab will show up when you are logged into your upgraded Quizlet Teacher account, and information will fill in as your students study the set.
You can choose to filter the most missed terms by class and by time period (past day, past week, past year).
To view which of your students have studied the set, add the set to a class and make sure your students are class members. Then select this class in the "View progress by" drop-down. Hover over the mode icons next to your students' usernames to see when they studied. When a student has partially completed a mode, the mode icon will turn blue; when the mode has been fully completed, the square will turn blue with the icon in white.