It has been found that a bilingual's two languages are simultaneously active, both phonologically and semantically, during language use.   This activation is indicated by electrophysiological measures of performance. Not only is a person's dominant language (L1) active when using the less dominant language (L2), but their L2 is also activated when using L1. This happens once the individual is adequately proficient in the L2.  They are both active when listening to speech, reading words in either language or even planning speech in either language.     Also, both languages are activated even when only one language is needed by the user.  
When comparing closed versus open authoring approaches, it is worth looking at the history of Wikipedia, which has succeeded in creating the largest encyclopedia in history. Wikipedia was preceded by the Nupedia  project, which also aimed to build a free content encyclopedia. Nupedia was not an open wiki like Wikipedia and adopted an extensive process of peer review before final publication of an article. After years, Nupedia had only completed 24 Articles, with 74 more articles as work in progress. Clearly this authoring model was not scalable, and was a strong motivation for Jimmy Wales, the founder of Nupedia to open up the authoring model by starting the Wikipedia project.