2 resultados para online discussion environments

em Massachusetts Institute of Technology


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The MIT Prototype Educational Assessment System provides subjects and courses at MIT with the ability to perform online assessment. The system includes polices to handle harassment and electronic "flaming" while protecting privacy. Within these frameworks, individual courses and subjects can make their own policy decisions about such matters as to when assessments can occur, who can submit assessments, and how anonymous assessments are. By allowing assessment to take place continually and allowing both students and staff to participate, the system can provide a forum for the online discussion of subjects. Even in the case of scheduled assessments, the system can provide advantages over end-of-term assessment, since the scheduled assessments can occur several times during the semester, allowing subjects to identify and adjust those areas that could use improvement. Subjects can also develop customized questionnaires, perhaps in response to previous assessments, to suit their needs.

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Increasingly used in online auctions, buyout prices allow bidders to instantly purchase the item listed. We distinguish two types: a temporary buyout option disappears if a bid above the reserve price is made; a permanent one remains throughout the auction or until it is exercised. In a model featuring time-sensitive bidders with uniform valuations and Poisson arrivals but endogenous bidding times, we focus on finding temporary and permanent buyout prices maximizing the seller's discounted revenue, and examine the relative benefit of using each type of option in various environments. We characterize equilibrium bidder strategies in both cases and then solve the problem of maximizing seller's utility by simulation. Our numerical experiments suggest that buyout options may significantly increase a seller’s revenue. Additionally, while a temporary buyout option promotes early bidding, a permanent option gives an incentive to the bidders to bid late, thus leading to concentrated bids near the end of the auction.