Essential Issues Of Usability In VEGA Information Grid

Information grid made information resource sharing and coordinated working possible using the technology of gird. The research on information grid includes that of subject, object, and that of communication between subject and object. Subject is the user of information grid while object is all kinds of resource in information grid.At present, the research on resources is of the most importance in the research field of information grid, while the research upon subject is of the second rank, let alone the study on usability in information grid. Dynamic modification is not only the primary character of information grid, but also the main factor that works on usability. The dynamic modification of subject in information grid involves the modification of users'basic information (such as the cell phone number, the address etc.), the information of user management (such as the modification of the host community) and the information of role. It will reduce usability if these modifications result in anomalies. How to find the causation of every anomaly; deal with the modification in time to insure the run of the system are main issues of this paper. How to analyze usability with measurable method is also an important aspect here.Focus on the emphases and the difficulties in the research upon information grid subject, we research on the behaviors of information grid subject from the point of view of space (the EVP three lays model of subject), time (the full life cycle) and evaluation (the evaluation of usability based on depths and widths) based on the achievements VEGA group have got in order to solve all or part of the usability issues in information grid. We focus on three main issues in this paper include issue of usability based on depths and widths with the system running naturally; issue of how to avoid the anomalies; issue of how to deal with the anomalies with less manual operations.An EVP space model of information grid subject is proposed in this paper. This model aims at the issues exist in the research on information grid subject and provides the methods as follows to solve the problems: using the virtual layer of subject to make information of access control and the resource the user want to use transparence to the user; using the virtual layer of subject and the mapping between the effective layer subject and the virtual layer subject to make the details of users'modification transparence to the user; using the virtual layer of subject to suit the modification of the role; using the host community to make independence management combined with the users management of the system; using the effective layer to solve the problem of users'using complexity.There are three main anomalies of the virtual layer subject information: add anomaly,...