Nikolaos Korfiatis

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Online reviews have received much attention recently in the literature, as their visibility has been proven to play an important role during the purchase process. Furthermore, recent theoretical insight argue that the votes casted on how helpful an online review is (review helpfulness) are of particular importance, since they constitute a focal point for(More)
Building on the interpersonal evaluation theory in social psychology, this study explores the existence of a negativity bias in evaluating the helpfulness of online reviews, i.e., whether users perceive a negative review to be more helpful than a positive review. An analysis of 7659 book reviews from Amazon.co.uk shows that a negativity bias disappears(More)
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 have been(More)
Online product reviews is an important advantage for consumers of experience goods in online marketplaces and act as a useful source of information during the purchase of a good. Furthermore in some online marketplaces consumers have the opportunity to evaluate how helpful a review was by using a binary evaluation interface provided by the online(More)
We present a new phrase-based generated list of opinion bearing words and phrases for the German language. The list contains adjectives and nouns as well as adjectiveand noun-based phrases and their opinion values on a continuous range between −1 and +1. For each word or phrase two additional quality measures are given. The list was produced using a large(More)
This paper discusses ways of navigating online contact networks networks of social connections defined under a relational context on a way that can provide much more meaningful information to those that use them. In particular we use the concept of a weak and strong relational tie to address the different levels of social distance and express them using a(More)
Regulation of clinical practice is a characteristic aspect of the medical profession. Regardless of whether this regulation derives from government-sourced guidelines or materials from government-sponsored institutions, it results in a high production of information resources (institutional information resources), which are disseminated to the clinical(More)
The purpose of this study is to define a bibliometric indicator of the scientific impact of a journal, which combines objectivity with the ability to bridge many different bibliometric factors and in particular the side factors presented along with celebrated ISI impact factor. The particular goal is to determine a standard threshold value in which an(More)
Taking a structuration perspective while integrating reciprocity research in economics, this study examines the dynamics of reciprocal interactions in social Q&A communities. We postulate that individual users of social Q&A constantly adjust their kindness into the direction of the observed benefit and effort of others. Collective reciprocity emerges from(More)