Asynchronous, or epistolary, intervews are one-to-one interviews, often via email or other digital mediums. As in a sequence of written letters, a relationship between the correspondents can be established and developed over time, which builds relationship and trust.
Advantages
Allows time for reflection.
Both interviewees and interviewer can considered responses in their own time and at their own speed.
Includes participants (interviewees or researcher) who have various disabilities and/or long-term health conditions that prevent a telephone or face-to-face interview.
Provides an immediate text-based record of the interview.
Steps
Decide the length and format for the interview.
Asynchronous interviews can be carried out over days, weeks or months.
Agree on the form of communication with the participants.
Different platforms will have different impacts on the interactions. For example, using a work communication platform vs email or Facebook Messenger will likely shape the type of responses.
The goal should be conversation, not interrogation. Start with questions or topics that are less sensitive and allow the connection to deepen naturally.