There are a few people who are exempt from the green card interview, and a knowledgeable immigration lawyer can further explain how it works. Several exemptions are:
Applicants who are filing an adjustment of status application
Applicants who are filing a petition for immediate relatives
Applicants who have already been granted asylum or refugee status
Applicants who have already been granted withholding of removal or protection under the Convention Against Torture
Applicants who are the spouse or genetic-born child of a U.S. citizen
An applicant born to two U.S. citizen parents residing in the United States