As mentioned earlier, quality in manufacturing can be improved either by reducing the process variance and improving its mean, or by imposing stricter quality control. In Wikipedia’s context process improvement can mean formalizing the policies and procedures for article construction, standardizing the style and structure of articles, and better aligning editorial groups with article topics through better communication and selection. The stricter control of the final product would mean more frequent quality review and stricter enforcement of quality criteria. Interestingly, this study found that one of the ways Wikipedia improved the quality of its collection was to continuously increase the quality requirements for articles to remain in the collection. This not only reduced the collection’s quality variance at the low end, but also increased its mean characteristics without actually changing the production process.