If the column for a phenomenon is marked PRESENT whenever a condition is marked present, the condition is SUFFICIENT. In the above table, the phenomenon is present whenever A is, so the table shows that A is a sufficient condition for the phenomenon. That is, the presence of A is enough to guarantee the presence of the phenomenon.

If the column is marked ABSENT whenever a condition is marked absent, the condition is NECESSARY. The above table shows that C is a necessary condition for the phenomenon. That is, the absence of C is enough to guarantee that the phenomenon is also absent.

If the column for a condition contains both * - and it is the same as the column for the phenomenon, the condition is both SUFFICIENT AND NECESSARY. D is both sufficient and necessary for the phenomenon.