2. What is needed for the exercise:
2 persons, person # 1 and person # 2, who are
both blindfolded.
1 person, person # 3, who is not blindfolded.
The exact same materials for person # 1 and
person # 2.
3. With the materials of person # 1,
person # 3, who is not blindfolded,
builds something.
4. Person # 1 explains to person # 2 what person # 3
has built.
Person # 2 builds, with the materials he / she has,
what she / she hears that person # 1 explains.