Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This note axiomatically justifies a simple scoring rule for multiple-choice tests. The rule permits choosing any number, k, of available options and grants 1/k-th of the maximum score if one of the chosen options is correct, and zero otherwise. This rule satisfies a few desirable properties: simplicity of implementation, non-negative scores, discouragement of random guessing, and rewards for partial answers. This is a novel rule that has not been discussed or empirically tested in the literature.