text: FM 2-22.3 _________________________________________________________________________________
  Matrices
  12-18. Construction of a matrix is the easiest and simplest way to show the
  relationships between a number of similar or dissimilar associated items.
  The items can be anything that is important to a collection effort such as
  people, places, organizations, automobile license plates, weapons, telephone
  numbers, or locations. In analysis, matrices are often used to identify “who
  knows whom,” or “who has been where or done what” in a clear concise
  manner. There are two types of matrices used in human analysis: the
  association matrix, used to determine existence of relationships between
  individual human beings, and the activities matrix, used to determine
  connectivity between individuals and any organization, event, address,
  activity, or any other non-personal entity. The graphics involved in
  constructing the two types of matrices differ slightly, but the principles are
  identical.
  12-19. The association matrix (Figure 12-2) shows connections between key
  individuals involved in any event or activity. It shows associations within a
  group or associated activity. Normally, this type of matrix is constructed in
  the form of an equilateral triangle having the same number of rows and
  columns. Personalities must be listed in exactly the same order along both
  the rows and columns to ensure that all possible associations are correctly
  depicted. An alternate method is to list the names along the diagonal side of
  the matrix. This type of matrix does not show the nature, degree, or duration
  of a relationship, only that a relationship exists. The purpose of the matrix is
  to show the analyst who knows whom and who are suspected to know whom.
  In the event that a person of interest dies, a diamond is drawn next to his or
  her name on the matrix.
  12-20. The analyst uses a dot or closed (filled-in) circle to depict a strong or
  known association. A known association is determined by direct contact
  between one or more persons. Direct contact is determined by several factors.
  Direct associations include––
  • Face-to-face meetings.
  • Telephonic conversations in which the analyst is sure who was
  conversing with whom.
  • Members of a cell or other group who are involved in the same
  operations.