Just to be sure, does the field “median_dwell” mean the median value of the minimum dwell time by visitors (instead of visits) in minutes?

Dear all, I have a question about the field “median_dwell” when exploring the monthly pattern data. I have checked the website (Weekly Patterns | SafeGraph Docs) explaining fields, which indicates that the field “median_dwell” mean the median minimum dwell time in minutes. However, it is still unclear for me. Just to be sure, does the field “median_dwell” mean the median value of the minimum dwell time by visitors (instead of visits) in minutes? @ross_epstein_safegraph

It is the median value of the minimum dwell time of each visit, not per visitor-- so, if the same visitor visited the same place three times in a week, it would count as three data points to aggregate the median over for that POI.

@Chris_Tramel_SafeGraph Hi, Chris. If so, why does it call minimum dwell time? It seems that it only has one time record per visit, and thus it is one value which does not need to say “minimum”. Thanks for your quick response.

This is addressed in the places manual here: Places | SafeGraph Docs

I’ll quote the relevant section :slightly_smiling_face:

> We determine the median dwell time by looking at the first and last ping we see from a device during a visit. This is a minimum dwell because it is possible the device was at the POI longer than the time of the last ping.

I see. Thanks