Crazy high results
I have students that have up to 12,000 XP between 1 January 2019 and 5 June 2019. Is this possible? It shows them active between 44-52 days With but these students can barely Write a coherent sentence in Spanish. Is it physically possble that these students have actually earned this amount of Points or have they found a way to cheat the system?
Even if your students practiced to earn 50 XP per day, it isnt possible. There was a forum discussion that answers this. (https://forum.duolingo.com/comment/32478952) I’ll save you a lot of reading, for if you don’t want to or don’t have time to read it. Basically, if you practice duos first skill over and over, you can get butt loads of XP easily. You need to see what lessons they’ve done. Or, you can use a timed practice. It takes about a minute, and I believe you get one XP per correct answer, but if you tap/click a word in the question, it gives you the meaning. I hope this helps :)
Chances are they're cheating, it seems to me; see my comments (and their antecedents) in this thread. There are videos on Youtube detailing how to gain arbitrary XP on DL by activating local scripts in the browser console.
It's by no means impossible (though hardly easy) to get that much XP in five days through legitimate DL use, but if they're not actually learning anything from it in your judgement, then cheating seems the overwhelmingly-likely explanation.