Participant checks

Participant checks help you make sure people are real, in the right country, and take part only once.

Choose how a study checks people

1. Open the study and click Edit study details.
2. In the Participant checks section, choose a setting (see below).
3. Optionally, choose Countries participants should be in. Hold Ctrl or Cmd to choose several. Leave it empty for any country.
4. Optionally, tick Ask for the phone's location.
5. Click Save changes.

The settings are:

• Flag for the team: everyone can join. Anything unusual shows on the Participants page. This is the default.
• Block high risk from joining: Tor, a high risk connection, the wrong country or a device already in the study cannot join until you allow them. The rest is flagged.
• Off: no checks.

What is checked

Zolensa checks when a participant signs the consent form, once a day when they open the study app, and when they share their location. Each finding is high, medium or low.

The connection, looked up with IPzentra, gives the country and city. It is flagged for:

• a country that is not on your list: high
• Tor, or a connection IPzentra rates high risk: high
• a VPN, a proxy, or a data centre instead of a home or mobile network: medium
• a device clock set to a time zone in another country than the connection: medium
• the same connection as another participant in the last 30 days: low, as this is common in shared homes

The device is flagged for:

• the same device as another participant, meaning the same browser on the same phone or computer: high
• a device that looks like another participant's, with the same model and settings: low, as popular phones often match

The phone's location, when you ask for it, is named with OpenStreetMap. It is flagged when it is outside your countries (high), in another country than the connection (medium), or not shared (low).

Test participants are checked, but never stopped from joining.

What participants are told

The consent page says: "To keep the study fair, we check the country of your internet connection and recognise the device you use, so no one takes part twice. We do not see your browsing."

If you ask for the location, it adds that sharing is their choice, and shows a Share my location button. Until they share, the app's Today screen shows a Confirm where you are card. They can take part without sharing.

When someone is stopped at joining

In a study set to block, a person with a high finding at joining is not let in and their consent is not saved. They see "We need to check something first" and are asked to turn off any VPN or proxy and open their link again. They show as Needs a look. Click Looks fine, allow, and they can open their link again and join.

The Participants list

The Check column shows Not checked yet, Checked, Needs a look or Blocked, with the number of findings and where they connect from. Hover over it to read the findings.

A medium or high finding means Needs a look. Low findings alone still show as Checked.

The Needs a look and Blocked tabs, next to the status tabs, list those people when there are any.

A participant's Checks section

Click a participant's code to open their page. The Checks section shows every open finding with its level and time, where they connect from, their Phone location with a Map link, and their device, with the codes of anyone else on the same device.

• Looks fine, allow: these findings no longer count. Anything new still flags them.
• Block: they can no longer open the study. They see that their access is paused by the research team. They can still read help and leave the study.
• Unblock: they can open the study again.

Open All checks for the full history, with a Map link for each shared location.

Owners and researchers can allow and block people. See Roles.

On the Home dashboard

In the Running studies table on Home, the Checks column shows Off, All fine, or how many people to look at, with a link to the Needs a look list.