Table 3.

Description of the sensor data.

Name	Description	Type	Values
timestamp	Timestamp of SDS data collected by access point in ISO 8601 format, timezone is CEST	String	YYYY-MM-DDTHH:mm:ss
day	Event day	Integer	1 = 2020-08-28
			2 = 2020-08-29
			3 = 2020-08-30
reporting_tagid	SDS tag id reporting contact	Integer	146–1176
reporting_qid	Unique person identifier wearing reporting SDS	Integer	11–998937
opposing_tagid	SDS tag id opposing contact	Integer	146–1176
opposing_qid	Unique person identifier wearing opposing SDS	Integer	11–998937
n_incidents	Number of contacts	Integer	0–224
timeslot	Time slot number	Integer	2–11
direction	Walking directions	Integer	0 = no directions
			1 = unidirectional
			2 = bidirectional
pre_q	Completed pre-questionnaire	Integer	0 = not completed
			1 = completed
post_q	Completed post-questionnaire	Integer	0 = not completed
			1 = completed
linked	SDS linked to household / group members	Integer	0 = not linked
			1 = at least 1 linked SDS
linked_id1	SDS tag id of first linked SDS	Integer	146–1176
linked_id2	SDS tag id of second linked SDS	Integer	146–1157
linked_id3	SDS tag id of third linked SDS, note no groups of 4	Integer	NA
location_tag	SDS has fixed location in art fair, note location tags do not have a QID	Integer	0 = SDS worn by visitor
			1 = fixed location SDS

QID is unique per person, while tag ID refers to the SDS and was handed out to multiple visitors during the art fair. A contact between two SDSs was registered on both sensors. Each sensor sent the data to the access point with their ID as reporting ID, and the other as opposing ID. When visitors from the same household linked their SDSs, their contacts were not registered.