Wikipedia is a well known online encyclopedia. It is based on a collaborative authoring principle. The Wikipedia attracts millions of visitors and they are allowed to read, edit or create new articles. Being open to everyone, makes Wikipedia the biggest online encyclopedia on the other hand, this statement leads to some negative features on the Wikipedia: erroneous facts and personal opinion propagation. Wikipedia Recommender System (WRS) is a collaborative filtering system that makes it easy to determine the quality of an article and allows users to submit the ratings and categories. Once the article classification was implemented into the WRS, the classification scheme started playing a vital role in determining the user's expertise area. To evaluate people agreement on classification of the Wikipedia articles, the survey is arranged. It investigates four different information classification schemes: Citizendium, Dewey Decimal Classification, Open Directory Project - Dmoz and top-level Wikiportals. The purpose of survey is to determine the scheme which enables people to classify articles the most consistently with the highest agreement level on it.