Clustering is finding groups of objects such that the
objects in one group will be similar to one another and
different from the objects in another group [7]. In
educational data mining, clustering has been used to
group students according to their behavior. For
example, Romero in [18] used clustering to distinguish
active students from non-active according to their
performance in activates. According to this clustering,
instructor groups active students with non-active
students for better students' performance.
In our case we used Expectation-Maximization
Algorithm (EM-clustering) to cluster the given data. An
EM algorithm [5][4] is a mixture based algorithm that
finds maximum likelihood estimates of parameters in
probabilistic models. In our case, we used EMclustering
to group students according to their
performance. Figure (5.3) gives Mean of each cluster
for each attribute. Using these results we can divide
students into five groups and guide them according to
their behavior.