You can find the Employee Report in the Reports section in the top left drop down.
Put in the date range you want to look at to get a report that looks similar to this one. On the very right hand side you will see an assigned ranking.
That ranking number is calculated as follows:
Avg Score - 30% weight
% of Excellents - 20% weight with higher scores weighted more heavily than low scores.
# of jobs - 30% weight
Response Rate - 20% weight
The up/down arrows next to the average score & total surveys sent::
If you check the top of the columns, there's a standard deviation listed. The down arrow appears for employees that have a score or number of surveys less than the mean minus the standard deviation. So if they are outside the standard deviation they have the down arrow.
These areas are just a way to help you, management, track down statistically significant variances that you might want to investigate the cause of those deviations.