Classical voting rules assume that ballots are complete preference orders over candidates. However, when the number of candidates is large enough, it is too costly to ask the voters to rank all candidates. We suggest to fix a rank k, to ask all voters to specify their best k candidates, and then to consider "top-k approximations" of rules, which take only into account the top-k candidates of each ballot. We consider two measures of the quality of the approximation: the probability of selecting the same winner as the original rule, and the score ratio. We do a worst-case study (for the latter measure only), and for both measures, an average-case study and a study from real data sets.

中文翻译：

---

从截断选票中近似投票规则

经典投票规则假设选票是对候选人的完整偏好顺序。但是，当候选人数量足够多时，要求选民对所有候选人进行排名的成本太高。我们建议固定一个排名 k，让所有选民指定他们最好的 k 名候选人，然后考虑规则的“top-k 近似值”，它只考虑每次投票的前 k 名候选人。我们考虑近似质量的两个度量：选择与原始规则相同的获胜者的概率，以及得分比率。我们进行了最坏情况研究（仅针对后一种措施），对于这两种措施，我们都进行了平均案例研究和来自真实数据集的研究。