Folksonomy was originally "the result of personal free tagging of information [...] for one's own retrieval",[5] but online sharing and interaction expanded it into collaborative forms.
This type of folksonomy is commonly used in cooperative and collaborative projects such as research, content repositories, and social bookmarking.
[17] Users apply tags to documents in many different ways and tagging systems also often lack mechanisms for handling synonyms, acronyms and homonyms, and they also often lack mechanisms for handling spelling variations such as misspellings, singular/plural form, conjugated and compound words.
A folksonomy emerges when users tag content or information, such as web pages, photos, videos, podcasts, tweets, scientific papers and others.
Strohmaier et al.[18] elaborate the concept: the term "tagging" refers to a "voluntary activity of users who are annotating resources with term-so-called 'tags' – freely chosen from an unbounded and uncontrolled vocabulary".
Folksonomy also includes a set of URLs that are used to identify resources that have been referred to by users of different websites.
These systems also include category schemes that have the ability to organize tags at different levels of granularity.
While both broad and narrow folksonomies enable the searchability of content by adding an associated word or phrase to an object, a broad folksonomy allows for sorting based on the popularity of each tag, as well as the tracking of emerging trends in tag usage and developing vocabularies.
[24] Critics claim that folksonomies are messy and thus harder to use, and can reflect transient trends that may misrepresent what is known about a field.
[27] Folksonomy is unrelated to folk taxonomy, a cultural practice that has been widely documented in anthropological and folkloristic work.
Folksonomy allows large disparate groups of users to collaboratively label massive, dynamic information systems.
[29] Folksonomy looks to categorize tags and thus create browsable spaces of information that are easy to maintain and expand.
[30] Common uses of social tagging for knowledge acquisition include personal development for individual use and collaborative projects.
Social tagging is used for knowledge acquisition in secondary, post-secondary, and graduate education as well as personal and business research.
Therefore, a user's current cognitive constructs may be modified or augmented by the metadata information found in aggregated social tags.
[32] The co-evolution model focuses on cognitive conflict in which a learner's prior knowledge and the information received from the environment are dissimilar to some degree.