My limited experience: Wikipedia actually works
The collaborative nature of Wikipedia has always been a controversial component of its character. Critics question the ability for a resource that can be edited by anyone to be taken seriously, warning that truth by consensus makes it too easy for misinformation to spread. Andrew Keen criticizes Web 2.0 itself in his book The Cult of the Amateur: How blogs, MySpace, YouTube, and the rest of today's user-generated media are destroying our economy, our culture, and our values
At the time of this writing Wikipedia is the sixth most-visited website on the Internet according to Alexa, beaten only by Google, Facebook, YouTube, Yahoo, and Baidu. With a community that large peer review catches obvious misinformation, and articles are created and updated in a timely manner as events occur. If a page is purposely vandalized, it is often detected and reversed in a manner of minutes. Within this large pool of visitors, there are professionals actively maintaining and reviewing articles.
My limited experience as a Wikipedia contributor demonstrates its effectiveness. Back in college I took a course on Latin America, a subject I had little knowledge of. To supplement my textbooks I would read Wikipedia articles. Many items I read about in my textbooks did not have a Wikipedia entry, one of which was the 1857 Constitution of Mexico. I decided to start that article using the little knowledge I had. I am not a prolific contributor to Wikipedia, having made less than a dozen edits. I am simply an avid visitor who saw an opportunity and took a little time out of my day to make some knowledge more easily accessible. I figured that a constitution that was in place for sixty years in what is now the eleventh most populated country on Earth deserved at least a mention on Wikipedia.
My article entry was very short and contained only a few of the basic details:
The Constitution of 1857 was a liberal constitution drafted in Mexico during the presidency of Ignacio Comonfort and vice-presidency of Benito Juárez. It instituted liberal policies including the freedom of speech, the press, and assembly. It guaranteed basic civil liberties for all Mexicans, reaffirmed the abolition of slavery, secularized education, and greatly curtailed the power of the Catholic Church. This constitution, along with the Plan of Ayutla and other liberal reforms, polarized Mexican society and led to the War of Reform.
About a month later a professional, a part-time lecturer on Mexico and Latin America at the University of Michigan according to their Wikipedia user page, found the article and greatly expanded upon it. The article's word count instantly jumped from 81 to 501. Without the basic article already in place, this individual may not have felt compelled to share their expertise on the subject. The article after his or her update can be read below:
1857 Constitution of Mexico
Over six years have passed since the article began and it looks nothing like it used to. It is now complete with images, references, a bibliography, and external links. It was also changed to a different title in order to accurately reflect the constitution's official name. You can read the article in its current state below:
Federal Constitution of the United Mexican States of 1857
So there you have it, a Wikipedia success story. I am not saying that Wikipedia should be the absolute standard by which all knowledge is judged. If you have a need for professional information than by all means, consult professionally published material from an expert. I am simply saying that Wikipedia can be consulted for reference in our daily lives and that much of it can be trusted thanks to extensive peer review from the large pool of Wikipedia visitors. When in doubt, check another source for verification.