分众分类法（Folksonomy），是一个英语合成词，中文译名尚未被普遍认同，又称「大众分类法」。由社会性书签服务中最具特色的自定义标签（Tag）功能衍生而来。

大众分类法（Folksonomy）是由“Folks”和“Taxonomy”组合而来，Folks在英文中是比较口语化的词，表示一群人，一伙人的意思。Taxonomy则是指分类法，它是信息架构（Information Architecture）中一个重要部分。而“Folksonomy”是指“群众”自发性定义的平面型非层级结构式标签分类，现有“分众分类法”，“通俗分类法”，“大众分类法”，“民众分类法”，“俗民分类法”等不同的翻译名称。

A folksonomy is a system in which users apply public tags to online items, typically to aid them in re-finding those items. This can give rise to a classification system based on those tags and their frequencies, in contrast to a taxonomic classification specified by the owners of the content when it is published. This practice is also known as collaborative tagging, social classification, social indexing, and social tagging. However, these terms have slightly different meanings than folksonomy. Folksonomy was originally “the result of personal free tagging of information [...] for one’s own retrieval.”. Social tagging is the application of tags in an open online environment where the tags of other users are available to others. Collaborative tagging (also known as group tagging) is tagging performed by a group of users. This type of folksonomy is commonly used in cooperative and collaborative projects such as research, content repositories, and social bookmarking.