comparison rule a rule that defines agreement, various levels of partial agreement and disagreement between the values in a particular field to be compared in two records. Thus a c. r. is a function of the values (ai, bi) in the field (i) being compared. When we consider multiple fields, the set of c. r. is a vector and is usually symbolized by the Greek letter gamma () (cf. Tepping, 1968, p. 49); it is a component of a linkage rule. [Cf. RLG Chapter 6, §2, ¶1 ]