Hi Safegraph team, I have a question regarding the coverage of core poi data. Do different versions of core poi cover the same stores in reality? If not, what’s the difference between historical version and the current version? Do monthly patterns and core poi cover the same POIs? It seems that I could only match a subsample of core poi to the monthly patterns using their safegraph_place_id. I was wondering what’s the criteria for a POI appearing in the monthly patterns data? Thanks!
I have a question regarding the coverage of core poi data. Do different versions of core poi cover the same stores in reality? If not, what’s the difference between historical version and the current version?
Also, I’m wondering what’s the sampling method used by Safegraph? And how are visit counts and visitor counts in the monthly/weekly patterns data collected? Does it only include the counts of visitors who have downloaded some application or use some certain devices or the counts reflect the actual total visit/visitor counts reported by the POI itself?
@Qianyang_Zhang_Columbia_University We obtain a variety of information from trusted third-party data partners such as mobile application developers. We collect this Information primarily through APIs, which are interfaces through which these app developers can provide us with information about their users.
as for the first part of your question. I’m not really sure what you are asking here. Are you asking what the difference is between our historical core POI data and our current core POI data?
Thank you! For the first question, I noticed that on the UI of
For the first question, I noticed that on the Safegraph data download page, in Monthly Places Patterns (aka “Patterns”) May 2020 - Nov 2020, there is also a version of monthly patterns called ‘patterns_backfill’, which contains the monthly patterns data starting from Jan 2018. I was wondering what is the difference between this data and the data in Monthly Places Patterns (aka “Patterns”) Jan 2018 - Apr 2020?
For the second question, I noticed that a significant number of POIs have visit counts less than 10 in a month, I was wondering does it mean that there were actually only 10 visits to that POI in that month, or does it mean that among the all visits to that POIs, the number of visits made by those visitors who have downloaded some applications equals 10 in that month?
@Qianyang_Zhang_Columbia_University to answer your first question:
A SafeGraph Patterns backfill is a restatement of historical foot traffic activity using the latest version of Core and Geometry to inform the recalculation. Our historical data (2018 data) has gone through this process and this is the difference between this backfill data and the regular patterns data
As for the second question:
since we can only be certain regarding the ten devices that we collected the data from, the data is representative of the 10 visitors who have applications that collect our data
Let me know if you have any more questions.