By
looking at the relationships between the numbers of correct answers
and the time durations that students spend in taking tests, we
have found that there are typical three patterns. The patterns
of the time durations spent in taking the test to each number of
correct answers depends on the difficulties of the questions. To
easy problems to solve, some smart students can use less time to
solve the problems and students with low academic ability need
much time to solve. To moderate problems to solve, every student
requires the similar time duration to solve the problems. To difficult
problems to solve, many students tend to use full time to the prespecified
time duration, but some students with low ability may give up tackling
the problem soon. 




success/failure
prediction, item response theory, nearest neighbor, similarity,
online testing, learning analytics. 

