Knol is a Google project which aims to include user-written articles on a range of topics. The project was  announced on December 13, 2007 and opened in beta to the public on July 23, 2008. When it was opened, there were a few hundred articles mostly about health and medicine.

Knol pages are "meant to be the first thing someone who searches for this topic for the first time will want to read", according to Manber. The term knol, which Google defines as a "unit of knowledge", refers to both the project and an article in the project. Several experts see Knol as Google's attempt to compete with Wikipedia, while others point out the differences between the projects.

Content 
Anyone can create and own new knols. There can also be several articles on the same topic, each written by a different author.
Because multiple articles can have the same title, readers find a topic by searching, rather than just by title. The authors can say who can edit their articles: the public, other authors, or only themselves. They may also choose to include ads from Google's AdSense to their knols. Knol has a policy that specifies topics that are unacceptable for the project. Relevant nudity is allowed (in most countries), but pornography, commercial or otherwise, is forbidden. Also forbidden is discriminatory or violent content. Content designed to promote businesses, products or services is allowed, but articles devoid of substantive content and created solely to generate ad revenue are not.

In its early stages of development as a resource, Knol was criticised very much. Commentators have called it a "wasteland" of articles copied from other sources, entries that were outdated or abandoned, as well as spam or self-promotion. Knol is frequently criticized for having incomplete and inaccurate articles. Google has said that "Since knol authors receive attribution, knols are a great forum for expressing your opinions." In October 2008, Google unveiled using Knols as a forum for debate, and enabled French, Italian and German versions, in the face of stagnating traffic.

Process 
Anyone who wants to contribute to Knol must first sign in, with a Google account. The users should give their real names. If permission is given, Google will check if the name is true. Google will do this by credit card or phone. Google "[believes] that knowing who wrote what will significantly help users make better use of web content". The company hopes that "knols will include the opinions and points of view of the authors who will put their reputation on the line".

Readers who are logged in with a google account can comment on entries, rate them or suggest changes. This works much like a blog. When the project was announced, Manber said that "Google will not serve as an editor in any way, and will not bless any content. All editorial responsibilities and control will rest with the authors."

All knols are licensed by default under the Creative Commons CC-BY-3.0 license. This license allows anyone to reuse the material as long as the original author is named, but authors may choose the CC-BY-NC-3.0 license (which prohibits commercial reuse) or traditional all rights reserved copyright protections instead.

Knol has "nofollow" outgoing links, using an HTML directive. This prevents links in its articles from influencing search engine rankings.

What people say about Knol 
People have described Knol as a rival to other encyclopedia sites such as Wikipedia and Scholarpedia. Sometimes people pointed out that the format was very different, and therefore it might be an addition to these sites. It might allow to get around some of the Problems of Wikipedia. The non-profit Wikimedia Foundation, which owns the name Wikipedia and the servers hosting the Wikipedia projects, welcomed the Google Knol initiative saying that "The more good free content, the better for the world." Wikipedia articles are written collectively under a "neutral point of view" policy,

There has been debate whether Google search results can remain neutral because of possible conflict of interest. According to Danny Sullivan, the editor of Search Engine Land, "Google’s goal of making Knol pages easy to find on search engines could conflict with its need to remain unbiased." Jeff Chester, executive director of the Center for Digital Democracy, raised similar concerns: "At the end of the day, there's a fundamental conflict between the business Google is in and its social goals. What you're seeing here, slowly, is Google embracing an advertising-driven model, in which money will have a greater impact on what people have ready access to."

References

Other websites 

Knol Homepage 

Google