432 Studying How E-Markets Evaluation Can Enhance Trust in Virtual Business Communities
Additionally, further improvements to this neighborhood-based algorithm can be carried out,
as for example the weighting of the neighbors’ total utilities u (k ) ( d ∈ D ) according to how
similar they are to the active user a. Therefore:
∑z ud (k′) × sim
ua ( k') = ------±
∑d=1sima,d (7)
This normalization formula gives more weight to the opinion of the business partners whose
priorities are closer to the ones of the active user, than the other partners in the neighborhood.
Based on the estimation of the utility u (k ) for each candidate e-market, the e-market
recommendation algorithm can rank the alternatives and present the active user with a
prioritized list of recommended e-markets.
4. Case scenario
In this section, we briefly present the applicability of the proposed recommendation algorithm
to support the members of a VC of agribusinesses, who are interested in finding trustful e-
markets with certified organic products. This scenario is envisioned in the context of the
online services that the BIO@GRO portal, a large Web portal for the OA sector, is expected to
provide. BIO@GRO (http://bioagro.aua.gr) is a European project that aims provide OA actors
(e.g. farmers, processors, consumers) with a variety of online services, including information
catalogues, educational and e-government resources, as well as, e-business and e-commerce
resources. In this context, the BIO@GRO portal is going to host an Internet-based directory of
e-markets that offer organic products (Manouselis & Costopoulou, 2005). The visitors of the
BIO@GRO Web portal will be able to register in particular services, formulating thus VCs of
people with common interests and needs.
We therefore assume the hypothetical scenario of a VC of agribusinesses that are interested in
organic products. The members of this VC are expected to use the BIO@GRO discussion
forum and communication capabilities in order to exchange opinions and experiences, related
to the production and trade of organic products. They are also expected to use the Internet-
based directory of OA e-markets, in order to find ones with organic products that are
appropriate for their needs. In this scenario, we introduce the VC members with the possibility
to contribute their overall satisfaction from e-markets that they have transacted with (that is,
evaluate them using the WebQual instrument). The evaluation results are stored in the Web
portal according to expECEM. We have to note here that, at this level of analysis, the type of
products that an e-market is offering is not considered in the evaluation criteria. Thus, we
assume that all e-markets more or less offer the same kind of organic products. In this way, a
common pool of experiences with e-markets is created, which every VC member can share and
take advantage of.