When viewing the Markbook for a class, you can choose between three views:
By default, the Markbook starts out showing you students' last attempts. You can change the view by clicking the dropdown at the top of the page:
The Markbook will show the test results of all the students who are currently in the class you've selected. That includes tests that the students took before they were in that class.
If you'd like to view more detail about test attempts, you can view the results for individual tests. Do this by selecting the test you want to view from your My Educake page, and clicking "View next attempts at test".
You can also monitor progress on topics through Track Progress.
For more information on how to do this, please see the article below: