A discussion of wikis would be missing something without at least some mention of the most widely accessed wiki in the world: Wikipedia. There is quite a bit of debate among educators about the use of Wikipedia for school assignments. Whatever policies may be implemented within the classroom, however, you can be sure that students will be looking at Wikipedia when they do online research, since it’s often one of the top few links to pop up with any web search on a particular topic. One of the other teachers in the Web 2.0 course I am taking described how a discussion of the positives and negatives of Wikipedia can be a “teachable moment” for students.
The majority of teachers at my school do not allow the citing of wikipedia as a source. I also caution my students against using wikipedia even as a starting point for their research on particular assignments. Though everyone who registers is free to contribute and correct mistakes, and most information on Wikipedia is generally accurate, the reality is that much misinformation exists on wikipedia, especially in more controversial issues in which the conventional wisdom is actually incorrect. Some examples:
My first foray in editing wikipedia was to correct a misrepresentation of an Augustine quote on the "Science and Religion" entry. Augustine was previously quoted as saying that Christians must beware of mathematicians because they may have made a covenant with the devil, but what Augustine was actually referring to was astrologers rather than mathematicians. I was able to spot the misrepresentation because I had background knowledge about Augustine, but if my students had seen that quote and didn't investigate more deeply, they may have concluded that Augustine was an example of how Christians are opposed to science and mathematics.
I think that where I am most concerned about the reliability of wikipedia is in those articles that deal with controversial issues or topics in which the majority opinion is erroneous or biased. For example, the current wikipedia entry on "Intelligent Design" contains much that is factually incorrect and biased against ID. However, corrections of these errors are often quickly reverted by those who appear to have an agenda against Intelligent Design and its proponents. This entry certainly does not follow Wikipedia's "Neutral Point of View" and "Verifiability" policies, but it is difficult to present the balancing facts because the great majority of people who are editing this entry hold--either knowingly or unknowingly--a biased or at least incomplete view of the topic.
William Dembski, one of the key proponents of Intelligent Design, has tried many times to correct erroneous information presented on the wikipedia page about him, but his corrections are repeatedly deleted such that what someone reads about him on Wikipedia is an inaccurate and biased portrayal. These serve as examples of how at times conventional wisdom or the majority position can be unreliable, and that this can make it difficult for a minority position to accurately assert itself.
One of the top students at our school wanted to make a point about wikipedia. His history class had to write a research paper on a particular topic. This student created a new page on Wikipedia addressing this topic, and it was so convincing that the information made up by this student was cited by several other students in the class in their research papers! It was only after the student explained what he had done that people realized how deeply they had been taken.
I think that the most useful aspect of wikipedia is the links to the sources used for the content posted on the page. Many of those links are indeed good quality, and students can see from the context whether the content that is presented on wikipedia is accurate or not. But even then, the neutrality of the content is not guaranteed, since pertinent information that may contradict what is presented in the wikipedia entry may be ignored.
If students approach Wikipedia with a skeptical eye and the understanding that it is not necessarily unbiased, accurate, or complete, then Wikipedia can be a useful resource. But the problems come when students rely too much on what they obtain from Wikipedia.