I think this has been discussed but its worth mentioning - I had 2 shops for Marketforce right next to each other....I got the message below...they may invalidate my shops due to the end time of the first one and start time of the second not being 6 minutes apart....
MESSAGE FROM MF HELP DESK:
Your shops should not be completed less than six (6) minutes apart from each other. If there is less time between shops, they will be subject to receiving an Overlapping Times infraction, which could result in one or both of those shops being invalidated. We consider shops that are completed closer together than six (6) minutes may not have the quality that we expect.
Before you start each next shop, you should review your Questionnaire hard copy for the next shop so that you can be reminded of what data you will need to collect. After you complete a shop, you should spend some time in private completing your Questionnaire hard copy with the data obtained during that shop. If you do this, you are recording that very important information while it is fresh in your mind, thereby helping to ensure reporting accuracy.
Only when you have recorded the information from one shop, and cleared your mind so that you can undertake your next shop with an objective and refreshed mindset, and you have reviewed the material for the next shop, should you proceed to your next shop.