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with all most thousands of pre-assessed essays
(corpus). Then, once the essay input is given, it
gives the grade and as well as a proper feedback
to improve. Hence some of these systems can be
used for self-learning by students as well as by
the teachers or institutes for grading huge amount
of essays. Today (from 2007) the internationally
recognized TOEFL exam gives the grade to the
students' essays as a combination of human &
machine assessment.
cases are complemented with statistical based
approaches. How come it comes under Artificial
Intelligence? The time, machine can grade human
written essays, which requires some expertise,
we can tell that this is Artificial Intelligence. As
because, the commonly available systems cannot
perform that task. Text categorization is the prob-
lem of assigning predefined categories to free text
document. The idea of automated essay grading,
based on text categorization techniques, text com-
plexity features and linear regression methods was
first explored by Larkey (1998). The underlying
idea of this approach relies on training of binary
classifiers to distinguish “good” from “bad” essays
and on using the scores produced by the classifiers
to rank essays and assign grades to them. Several
standard text categorization techniques are used
to fulfill this goal: first, independent Bayesian
classifiers allow assigning probabilities to docu-
ments estimating the likelihood that they belong
to specific classes; then, an analysis of the occur-
rence of certain words in the documents is carried
3. HoW tHE AEg SyStEmS Work?
AEG systems are a combination of any two, three
or all the techniques mentioned here - NLP (Natu-
ral Language Processing), Statistics, Artificial
Intelligence (Machine Learning), Linguistics and
Web Technologies, Text Categorization, annotated
large corpora etc. It must be noted that seven out of
ten most popular systems are based on the use of
Natural Language Processing tools, which in some
Figure 2. A common framework for the existing automated essay grading systems
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