  We review some recent endeavors and add some new results to characterize and
understand underlying mechanisms in Wikipedia (WP), the paradigmatic example of
collaborative value production. We analyzed the statistics of editorial
activity in different languages and observed typical circadian and weekly
patterns, which enabled us to estimate the geographical origins of
contributions to WPs in languages spoken in several time zones. Using a
recently introduced measure we showed that the editorial activities have
intrinsic dependencies in the burstiness of events. A comparison of the English
and Simple English WPs revealed important aspects of language complexity and
showed how peer cooperation solved the task of enhancing readability. One of
our focus issues was characterizing the conflicts or edit wars in WPs, which
helped us to automatically filter out controversial pages. When studying the
temporal evolution of the controversiality of such pages we identified typical
patterns and classified conflicts accordingly. Our quantitative analysis
provides the basis of modeling conflicts and their resolution in collaborative
environments and contribute to the understanding of this issue, which becomes
increasingly important with the development of information communication
technology.
