"tagging eliminates the decision - (choosing the right category), and takes away the analysis-paralysis stage (...) it provides immediate self and social feedback (...) it taps into an existing cognitive process without adding add much cognitive cost"
"Tagging works because it strikes a balance between the individual and social. It serves the individual motive of remembering, and forms a ad-hoc social groups around it."
"Could the order of tags be a general solution for hierarchical tagging? It would be similar to relations between words within sentences or to the order of folders in a directory and without enforcing a structure."
C. Hayes, P. Avesani, und S. Veeramachaneni. ITC-IRST Technical Report. http://sra. itc. it/people/hayes/pubs/06/hayes-ijcai07-tech-report. pdf, (2006)