Assistants hand out pencils and paper. The audience members write out questions or comments, keep the paper they write on, and do or do not return the pencils. The performer is brought on to the stage, sat upon a chair facing away from the audience, covered with a light cloth, placed in a "light trance", and proceeds to read some of the comments and answer some of the questions. An assistant polls the audience to see if anyone holds the proper piece of paper; when found, s/he then asks the audience member to read the slip out loud, or sends a sub-assistant to do it if the person is shy.
The assistant, when handing out the paper, unobtrusively hands out also a piece of stiff cardboard for the audience members to write upon. They appear solid but actually have a slip of paper inserted in them; there is a small sheet of carbon paper on each side of the white paper. These are gathered up on some pretext or other. They are then passed to the performer who goes through them inconspicuously and answers the questions or comments upon the comments.
This trick is difficult to perform convincingly because everybody will suspect something when the pieces of cardboard are collected, so some convincing reason will have to be concocted. The performer can let it be known that he probably won't be able to read all the questions though his "force of mind" as the ability comes and goes. The cloth need not be very opaque, just enough so that small movements of the performer's hands won't be visible.