Multiple observations at the same location

I recently got a question via twitter:

@skyglowberlin Just wondering, would multiple measurements on different days on the LON app from the same location help or harm project?
— Aashay (@Crowning_Gory) March 2, 2014

Thanks for the question Aashay!

The answer is that multiple observations are extremely valuable to us, especially at this early stage. There are several reasons for this:

• Observations from multiple people at the exact same time are very useful, because it helps us understand how different people perceive the night sky and how they interact with the app.
• Observations from the same person at different times on a single night help us understand curfew effects (the sky over most cities gets darker as the night goes on).
• Observations from the same person on different days at about the same time within the same month help us understand how consistent the app's results are with changing atmospheric conditions and clarity, as well as with the changing stars that it asks you for (there is some randomness built in). 
• Observations from the same person several months apart are helpful for us because the stars change with the seasons. We are also trying to understand which stars are easier to decide upon and which are problematic, so the more stars you observe the better.

And finally, and most importantly, the main purpose of the app is to track long term changes in skyglow worldwide. For this to work, you need to sample the same location in a future year.

So please feel free to make observations as often as you like and observe as many stars as you like (going past 7 stars is helpful). But most of all, please plan to come back to the same location in the future and see if the sky has changed!