Information Technology Reference
In-Depth Information
Optimistic Percentage (OP)
method - makes an optimistic estimation of the points for
the answer. Its essence is to iterate over the keywords list and summarize their
percentage matches. Thus, the calculated amount of rates for each keyword, divided by
the maximum possible match (in %), gives the reduction coefficient. The actual number
of points for the answer is calculated by multiplying the maximum number of points by
the coefficient of the reduction. This method is more "tolerant'' to allowing spelling
mistakes in the answers, because low percentage matches are not ignored (unlike the
first method) and are included in the formation of the final amount of points.
When the calculations finish, the EA generates an answer as an ACL message, which then is
transformed by the environment into a SOAP Response message (a result from a web
service call). In the answer there is a parameter, representing the calculated amount of
points, extracted afterwards by the Exam Engine. A comparison of the scores, given by the
two methods and by the teacher, are presented in Figure 8.
Fig. 8. Comparison of WM, OP and the teacher for 18 tests
The FraudDetector will try to recognize any attempts to cheat in the answer given by the
student. Such attempts would be to guess the keywords or copy/paste results from Internet
search engines. This assistant cooperates with the Evaluator agent and if its receptors detect
a probability of a cheating attempt, it informs the Evaluator agent, which for its part informs
the assessing teacher that this answer requires a special attention, because it is a suspicious
one. The Statistician stores information about all processed answers with a full history of the
details from all calculating methods used by the Evaluator agent. This assistant needs a
feedback how many points are finally given by the teacher for each answer. Thus it
accumulates a knowledge base for each teacher and is able to decide which of the methods
best suits the assessment style of the current assessing teacher. Upon returning the results of
the Evaluator assistant, information by this agent determines which results from each
