Mariette DiChristina, editor-in-chief, Scientific American: Wikipedia underscores an evolutionary lesson: We've always gotten farther as a species collaborating than going it alone. As a longtime science journalist, I can't stop myself from looking at human endeavors through the lens of possible past selection pressures. Wikipedia reminds me of in-group information sharing.

Jonathan Lethem, novelist, Pomona professor: With all respect to the noble volunteer army, I call it death by pedantry. Question: hadn't we more or less come to understand that no piece of extended description of reality is free of agendas or ideologies? This lie, which any Encyclopedia implicitly tells, is cubed by the infinite regress of Wikipedia tinkering-unto-mediocrity.

Jay Rosen, NYU journalism professor: People who study online life are familiar with the One Percent Rule. It says that if 100 people gather at a given site, about 10 percent will contribute anything at all, even a comment at a blog post, and less than one percent will become deeply engaged as a regular contributor. The rest will just use the service.

Mary H.K. Choi, writer, bonne vivante: Wikipedia's a collaborative experiment akin to Winchester's account of the creation of the OED, which outlines Murray's mission to produce the tome. Murray was aided substantially by the offerings of Dr. William Chester Minor, a surgeon and lunatic murderer. Just as some contributors to Wikipedia will likely be.

Clay Shirky, technologist, writer, NYU professor: And this is what I think is really worth celebrating as Wikipedia begins its second decade. It took one of the best ideas of the last 500 years -- peer review -- and expanded its field of operation so dramatically that it changed the way authority is configured. So Happy Birthday, Wikipedia, and thanks for giving us so much to think about.

Ethan Zuckerman, fellow, Berkman Center: Mighty oaks from little acorns grow. From its idiosyncratic origins, Wikipedia has grown into a remarkably complete, authoritative and useful resource, dominating the reference space and serving as the first response to many online queries. It's the 5th most visited site on the Internet and the most visited non-commercial site.

Craig Newmark, founder, Craigslist: Wikipedia is the history of our times, where people work together, doing their best to write the truest versions of knowledge. It's an ongoing effort with a successful balance of professional and citizen curators, writers, and fact checkers. This has proven increasingly effective, not only in producing material, but in getting it corrected.





Yochai Benkler, professor, Harvard Law School: That's the biggest gift that Wikipedia has given to us -- a vision of practical utopia. What gift can we best give back? Perhaps it is just this, to recognize the transformative role that thousands of individuals have played for all of us in how we can imagine our lives together as productive, engaged, social beings.