In the group formation phase of the KJ method, many people misunderstand that they need to collect similar pieces. They see the relation based on similarities only. However, there are many other relations.

For example, "the opinion of A and the opinion of B conflict" is the relationship between A and B.

Fig: many types of relation

Similarity: A is similar to B

Conflict: A and B are in conflict

Inclusion: A includes B

Temporal change: It is A, and then it changes to B.

Causality: Because A, B happens.

Story connectivity: A. B.

When I say "collect pieces likely to be related" in the group organization phase, the relation can be all of above.