There are two ways to add student numbers in Talis Aspire Reading Lists (TARL):
1. At the list level: When creating or editing a list, these are list based student numbers.
2. At the Module level: When you upload student numbers in your Hierarchy update as described in the Hierarchy data format article.
The two sets of numbers are record separately in the data and one does not overwrite the other.
Reviews uses the student numbers on the reading list as first preference. Only if student numbers are missing at the list level will the module/unit level numbers be referred to.