Literally this. The education system is lazy and tests people only every 30 days, with a test or midterm. This is the system's fault. Quiz every day. Catch where people are struggling, early. The quiz can be on their phones and let you know when they switch apps. Just have them close their laptops, take out their phones, scan QR codes from the screen in front, or pasted on a wall, and then 5 min quiz on their phones. That's what I did.