Purpose – The purpose of this paper is to present an approach to evaluating contributions in collaborative authoring environments, and in particular, Wikis using social network measures. Design/methodology/approach – A social network model for Wikipedia has been constructed, and metrics of importance such as centrality have been defined. Data has been gathered from articles belonging to the same topic using a web crawler, in order to evaluate the outcome of the social network measures in the articles. Findings – Finds that the question of the reliability regarding Wikipedia content is a challenging one and as Wikipedia grows, the problem becomes more demanding, especially for topics with controversial views such as politics or history. Practical implications – It is believed that the approach presented here could be used to improve the authoritativeness of content found in Wikipedia and similar sources. Originality/value – This work tries to develop a network approach to the evaluation of Wiki contributions, and approaches the problem of quality Wikipedia content from a social network point of view

Purpose -Although issues on disaster prevention have extensively been studied in the literature and have been embedded in everyday library practices all over the world, the vast majority of Greek libraries have not developed any specific measures. This paper seeks to review several disaster management approaches for academic libraries and to make suggestions for Greek academic libraries by analyzing the results of a nationwide survey. Design/methodology/approach -The literature regarding disaster management approaches for academic libraries is reviewed and accompanied by a survey conducted in July 2010 in order to study the level of risk and disaster preparedness in Greek academic libraries. Findings -In Greece, disaster management within academic libraries seems to be dealt with inefficiently, if not completely neglected. The fearsome economic crisis is further degrading the level of disaster preparedness due to a number of side effects, including the lack of personnel and equipment maintenance activities, inadequate buildings and insufficient funding. Originality/value -While the literature is flooded with risk and disaster preparedness approaches based on the work undertaken in most Western countries, this is the only study presenting evidence on the level of preparedness for Greek academic libraries.

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In study we attempt to solve the problem of determining how authentic published images on the Internet are, and to what degree they may be identified by comparison to the original image. The technique proposed aims to serve the new requirements of libraries. One of these is the development of computational tools for the control and preservation of intellectual property such as digital objects, and especially of digital images. For this purpose, this article proposes the use of a serial number extracted using a previously tested semantic-properties method. This method, based on the multilayers of a set of arithmetic points, assures the following two properties: the uniqueness of the final extracted number, and the semantic dependence of this number on the image used as the method's input. The major advantage of this method is that it can serve as the authentication for a published image or detect partial modifications to a reliable degree. Also, it requires the better of the known hash functions that the digital-signature schemes use, and produces alphanumeric strings for checking authenticity and the degree of similarity between an unknown image and an original image. As an example of a possible application, this article suggests that this method could be incorporated into the well-known DOI system in order to provide a reliable tool for identification and comparison of digital images.

The following article summarises the results of the LIBACT1/GR project concerning the implementation of UNIMARC and CDS/ISIS in the National Library of Greece and the conversion of the existing records of the Library into the UNIMARC format. The article outlines the basic features of the CDS/ISIS implementation and describes a solution to the problems of implementing UNIMARC on this piece of software. A technique used for the automated UNIMARC formatting of the Library's bibliographic and authority records (from simple ASCII text original files) is also described and evaluated.