Questions about what constitutes knowledge are the purview of a field of philosophy known as ‘epistemology’, and the most general formula for understanding what constitutes knowledge is justified true belief. Deriving from Plato’s Theaetetus dialogue, the core of the idea is that we have knowledge when we hold a belief about the world that is true, and when we also possess a legitimate justification for that belief. I have reasons to question this model, but this will have to wait for another time. For now, it is sufficient to ask whether anyone relying on the Wikipedia can be said to possess justified true belief.
It is clear that there a good reasons for doubting that someone whose only source was the Wikipedia can form a justified true belief. In the first place, any time we refer to the Wikipedia, we have no way of knowing whether the information recorded there has been mischievously altered by someone, effectively at random. The open editorial policy means that we can never eliminate this possibility, which gives us reason to doubt the accuracy of anything read there. Furthermore, while the content policy means that any claim posted must be referenced to some other source, there are limited standards of quality control regarding this referencing: it is perfectly possible to accurately reference inaccurate claims, for instance. So we can also doubt that Wikipedia, by itself, provides any basis for legitimate justification. Indeed, the only times we can actually be confident that the Wikipedia has valid content in an article is when we know that topic from some other source. At which point, the Wikipedia has ceased to be a provider of knowledge at all, and has become merely an aide-mémoire; a means of reminding.
How does the Wikipedia differ from, say, a traditional encyclopaedia? The construction of a reference work of this kind involves an editorial team selecting experts in various fields to write articles that summarise topics relating to those fields. Clearly, the knowledge so recorded can still be wrong – examining early twentieth century encyclopaedias reveals the extent at which our knowledge has been substantially revised just in the last century – but where such a book is correct, we have at least a strong claim to justification: the expert who drafted the article text was selected precisely because of their knowledge of the field in question. We can, in principle at least, possess justified true belief if we start from a conventional encyclopaedia to a degree that cannot apply to the Wikipedia. The decisive point isn't the truth of either source: it is the lack of reliable claims to justification on behalf of the Wikipedia.
What this makes clear is that the way an encyclopaedia is supposed to record knowledge is based upon an appeal to the authority of experts. The problem with the Wikipedia is that the editors are in no way guaranteed to have expert knowledge, and neither are they necessarily qualified to distinguish expertise from its alternatives. This does not make Wikipedia useless: it functions as a giant ‘dial-a-geek’, whereby you can get an informed opinion via a random unknown nerd or cluster of nerds. It is likely to be correct when the information is straightforward (historical dates, for instance). But beyond trivia, its epistemological claims become increasingly sketchy. It certainly could contain factual information – but you can never be sure that what you are looking at does, if you don't have some other point of reference.
The Wikipedia knows nothing, or rather, someone using the Wikipedia cannot know anything from that alone. Whoever refers to a topic on the Wikipedia cannot be said to possess justified true beliefs (i.e. knowledge, conventionally construed), because no-one who edits the Wikipedia has been credibly selected for expertise, creating a gap in justification. Wikipedia editors have self-selected based on personal interest – which is why there are so many articles about (say) Star Trek and videogames. This process could still convey expertise – it frequently does about as well as any other encyclopaedia! – but we are never certain that it has done so in a subject we ourselves know nothing about. Even when Wikipedia provides correct information we cannot know it has done so, and thus can possess no justification for claiming that we do. I say this as someone who uses and even edits the Wikipedia on a regular basis, and who appreciates its remarkable virtue as a public database. It is not that particular resource that I am questioning, but the very idea of databases as a means of knowing. Kn0wledge, whatever it might be, becomes tainted with doubts when it is compiled using the kinds of techniques that lie behind the Wikipedia – and this in turn raises interesting questions about all our knowledge.
This enquiry continues in Factual Knowledge, next week.