Conversation so far:
Who first tested Eileen J. Garrett's abilities?
Eileen J. Garrett took part in clairvoyance tests. One of the tests was organized by Joseph Rhine at Duke University in 1933 which involved Zener cards.
Describe Eileen J. Garrett's clairvoyance test.
In Eileen J. Garrett's clairvoyance test, certain symbols were placed on cards and sealed in an envelope, and participants were asked to guess their contents.
What were the results of Eileen J. Garrett's clairvoyance test?
Eileen J. Garrett performed poorly and later criticized the tests by claiming the cards lacked a psychic energy called energy stimulus and that she could not perform clairvoyance to order.
What other tests were done on Eileen J. Garrett besides the one organized by Joseph Rhine?
The parapsychologist Samuel Soal and his colleagues tested Eileen J. Garrett in May 1937.

Question: How was this test performed?
Self-contained rewrite: How was Eileen J. Garrett's test with Samuel Soal performed?