The term assemblages has been employed to capture the multi-authored character of information goods produced through collaborations using the Internet as well as the modular nature of these information goods. Horizontal information assemblages, also referred to here as collections, were defined in terms of the by the nature of the complementarity dependency between the items. Such collections are like a library or encyclopaedia. Their value is increased by the inclusion of more volumes or articles, but they would still have value if one volume or article were missing. Vertical information assemblages, also referred to here as systems, were defined in terms of cumulative dependency among items. Their value may be catastrophically reduced if a single item is defective (having errors, omissions, or obscurities). These epistemological distinctions are important because they suggest different organisational arrangements. In horizontal information assemblages, there is less need to police, i.e. govern, the fit between components than in vertical information assemblages.(Definition from: Mateos, G. and Steinmueller, W. 2003. Applying the open source development model to knowledge work in http://www.sussex.ac.uk/spru/publications/imprint/sewps/sewp94/sewp94.pdf)