More than likely this is a company that uses the SASSIE report format. On your shop log for that company you will see your shopper rating in the boxes just below where it says "[Your Name] Shop Log". There is a line that should show your shopper ID, Total # of Shops (which you have performed for that company), Average Rating (that is generally your 'Score') and Last Shop Rating (rating for your most recent shop.
If you have performed no shops for the company yet, your Average Rating should be a 5.
Once you perform your first shop for the company, it will be scored and your Average Rating will go up or down from a 5. A really poorly done shop that is turned in on time and is not rejected is likely to get a 6, 7 or 8, so generally a score is less than 5 if you have failed to do a shop entirely or cancelled so close to the due date that the scheduler got pissy and gave you a 0 or a 1. Not all companies that use the SASSIE platform post your ratings on shops, though most do.