I found Apr, 2020 pattern data size are much smaller than other months. Anything reason for that? Here is the location for the April 2020 data: Monthly Places Patterns aka Patterns Dec 2020 - Present\patterns_backfill\2021\04\13\10\2020\04) @Jeff_Ho_SafeGraph
Can you elaborate what you mean by smaller? Total POIs, total visits, number of devices?
I could tell the total numbers of POI. Since I only picked one NAICS code.
Since you’re looking at the Patterns backfill, POIs won’t show up if they don’t have any visit data. And we saw a decline in POIs visits that month since it was the first one after lockdowns due to the pandemic. So I am guessing that the POIs with few visits “dropped out” that month due to fewer visitors recorded by our panel and in real life.
You could do a diff to see which POIs dropped out, and then look at how many visitors the dropped-out-POIs got in March 2020. If they got relatively few visitors (such that a sharp reduction would reduce their visit counts to 0), then that would be consistent with pandemic-related-dropoff
Thank you! Yes. The pandemic should be the reason. Since April number dropped suddenly, and May number jumped back. I thought it was a data problem.