You can read the conversations students had with a lesson's tutor while they were working.
Finding them
Open the classroom from the sidebar, go to Assignments, click the assignment and then the lesson.
On the Students tab, click the chat icon beside a student to read their conversation with the lesson's tutor. You can see what they were stuck on as well as what they wrote. The icon only appears when the lesson has a tutor.
Spotting a downvoted reply
In the list of submissions, the chat icon beside a student turns amber with a small thumbs-down when they gave one of the tutor's replies a thumbs down. Hover it to see Student downvoted a response, then click it to read the conversation. The reply they marked is highlighted.
This is available in every organisation by default. If your organisation has private student chats switched on, transcripts are hidden unless the classroom is a research classroom and the student has consented.