A composite weight is the sum of the individual weights for all field
comparisons for each record pair.
If a field agrees, the agreement weight (log to the base 2 of the ratio of the "m" and "u" probabilities) is used.
If a field disagrees, a disagreement weight is computed as log to the base 2 of the ratio of 1-m and 1-u. The result is a negative weight.
Therefore, agreements add to the composite weight, and disagreements subtract from the composite weight. The composite weight indicates that the higher the score, the greater the agreement.