 Here, a grade aggregation rule is said to be strategy-proof in grading if it satisfies two conditions: first, when an individual’s grade for an alternative \(x \in X\) is higher than the collectively assigned grade, then this individual can at most lower (and never raise) the collective grade for \(x\) by unilaterally changing his or her individual grade; and second, when an individual’s grade for an alternative \(x \in X\) is lower than the collectively assigned grade, then this individual can at most raise (and never lower) the collective grade for \(x\) by unilaterally changing his or her individual grade. Strategy-proofness in grading means that, when the goal is to assign collective grades to the alternatives in \(X\) and voters each seek to achieve collective grades that are as close as possible to their individual grades, they will not be incentivized to misrepresent their grades. In short, truthful expression of grades will be a (weakly) dominant strategy.