III: Small: Optimizing News and Opinion Aggregators for Diversity

观察家们对我们社会日益严重的政治两极分化提出了警告，对立的团体无法进行民间对话，以找到共同点或解决办法。 Digg、Reddit和Google News等聚合器依赖于评级和链接来选择和呈现每天生成的大量新闻和观点项目的子集。如果大多数评分者或链接者都有相同的政治观点，少数人的观点可能在结果中得不到代表，从而为多数人创造了一个回音室。 即使一个网站根据不同观点的人的投票或链接来选择项目，仅仅基于流行度的算法也可能导致多数人的暴政，有效地压制少数人的观点。这项工作是第一次尝试正式几个不同的情况下的一般概念的多样性的观点，并制定算法，优化这些措施。这些技术可能适用于其他领域，其中选择不同的项目集是有价值的，例如搜索引擎结果和观众对会议发言人或政府官员提出的问题进行投票。 本研究的目标是：1）形成多样性的结果集的替代措施; 2）开发算法选择结果集，共同优化多样性和流行性; 3）评估替代选择和呈现方法对人们使用汇总服务的意愿，他们接触不同意见的影响，和他们的论点库的大小。该项目的结果将提供一个更好的理解替代概念，这意味着一组项目是多样化或平衡，以及不同的人对不同层次和表现形式的多样性的反应范围。深入了解人们对可接受的支持和挑战的偏好，还可以创建新闻和意见聚合器，促使人们选择让自己接触更大的多样性，从而减少两极分化，加强民主。包括开放源码软件在内的成果将通过项目网站（http：//si.umich.edu/balance/）分发。

Observers have raised alarms about increasing political polarization of our society, with opposing groups unable to engage in civil dialogue to find common ground or solutions. Aggregators such as Digg, Reddit, and Google News rely on ratings and links to select and present subsets of the large quantity of news and opinion items generated each day. If a majority of the raters or linkers share a political viewpoint, minority viewpoints may get little representation in the results, creating an echo chamber for the majority. Even if a site selects items based on votes or links from people with diverse views, algorithms based solely on popularity may lead to a tyranny of the majority that effectively suppresses minority viewpoints. This work is the first attempt to formalize several different instances of the general concept of diversity of viewpoints and to devise algorithms that optimize for these measures. The techniques are likely to be applicable to other domains where selecting a diverse set of items is valuable, such as search engine results and audience voting on questions to ask of a conference speaker or public official. The goals of this research are to: 1) form alternative measures of diversity for result sets; 2) develop algorithms for selecting result sets that jointly optimize for diversity and popularity; 3) assess the impacts of alternative selection and presentation methods on people's willingness to use an aggregation service, their exposure to diverse opinions, and the size of their argument repertoires.The results of the project will provide a better understanding of alternative notions of what it means for a set of items to be diverse or balanced, and the range of reactions that different people have to varying levels and presentations of diversity. Insight into people's preferences for acceptable support and challenge may also allow for the creation of news and opinion aggregators that cause people to choose to expose themselves to greater diversity, thus reducing polarization and enhancing democracy. Results, including open source software, will be distributed via the project web site: (http://si.umich.edu/balance/).