Hi Kate, great questions!
First, all data, including CAT-MH data, remains within CIAS. Adaptive Technologies just deals with the licensing of the tool.
The other questions you've posed are going to have different answers based on the setting you're using, whethere participants have accounts or are anonymous.
"How is a participant’s name linked with their data across multiple survey sessions?"
In cases where participants have accounts
Participant names are excluded from the CSV file, even if the participant has a CIAS account. You would have to add either a free response or name screen to your intervention, asking the participant to to provide their name in order for it to present in the CSV file. The only identifiable information that is automatically included in the CSV file for registered participants, this their email address.
In cases where participants remain anonymous
If the intervention uses an “anyone with the link” (the anonymous setting), CIAS will generate an ID for this user where we would see an email if the user had an account. However, the ID will be different for each session and will look like a long complex email address, for example, 1699888268_97a0dc74dcf8336aa879@guest.true.
A new ID is generated for each session of the intervention. So, the data will not be contained in one line for each participant, as it is when participants have accounts. If you want to link data for anonymous participants across sessions, we recommend including a free response question where the user enters some kind of identifier, like participant ID, so you can link their data across sessions of your intervention. This identifier won’t be linked or saved to the participant’s CIAS account, it will just appear in the CSV.
Your last question, "If we are eventually able to create a user account with a phone number, will account registration require the same information from participant as creating an email account (first name, last name, etc.)?"
No, in the future, when we release an option for researchers to invite participants to an intervention via text, all additional identifiable information, including name and email address will be optional. The phone number will become the identifier for the participant in the CSV file. Just a reminder, the researcher will need the participants phone number in order to send an invitation to the intervention via text.