\label{Spreadsheet_Levels}
The course spreadsheet has three levels.

\index{course level spreadsheet}
The top-level is the "course level" sheet, which is not accessible to
students. It lists the export rows of all "student level" sheets (the
sheet that students get to see when they press "GRDS"). These in turn
import the export rows of all assessment level sheets.

The figure shows the spreadsheet hierarchy. 

\begin{figure}
\begin{center}\includegraphics[  width=0.80\paperwidth]{spreadsheet_hierarchy}
\end{center}
\end{figure}