Citation
Sani, Salisu Muhammad
(2016)
Fuzzy membership function and inference-based model for predicting student's knowledge performance.
Doctoral thesis, Universiti Putra Malaysia.
Abstract
Intelligent Tutoring Systems (ITSs) are special classes of E-learning systems
designed to provide adaptive and personalized tutoring based on the individuality of
students. The student model is an important component of an ITS that provides the
base for this personalization. During the course of interaction between student and
the system, a quantitative representation of the actual student‟s characteristics such
as the student‟s knowledge state is created based on the observations and predictions
the ITS made on each student. The student‟s knowledge is one of the most dynamic
characteristic of the student; so dynamic like a moving target. However, modeling
student‟s knowledge and diagnosis are complex processes that are characterized by
uncertainty and imprecision issues that affect the prediction of the student model.
Fuzzy logic is a form of multi-valued logic derived from fuzzy set theory. Its
methodology provides a definitive solution to problems of information that may be
construed as uncertain or imprecise.
A major gap in the existing approach is the absence of an important component of a
fuzzy logic controller, the membership function graph which is vital for the
management of uncertainty and imprecision in student's knowledge modeling.
Moreover, the prediction accuracies of 36% and 90% achieved by the existing
models is seen as another limitations in their performance. This study propose novel
fuzzy based membership functions and inference mechanisms to design a fuzzy logic
based control process which aimed at modeling student's knowledge performance
and further diagnosis. Successful design of this two vital fuzzy logic engines will
respectively enables the realization of more accurate fuzzy student models and the
necessary diagnosis on them. An approximate student model based on fuzzy
membership function approach enables making accurate predictions about the state
of student's knowledge. The main idea of proposing a novel fuzzy inference process
is to provides the necessary diagnosis on the propose fuzzy student model. The
inference process take outputs of a fuzzification process with membership functions
as input variables for a mechanism which is defined by fuzzy If-Then rules and logical operators, and then reaches the output space that produces a human like
decision by inferring on the propose fuzzy student models.
For the purpose of this research, the training data which is an instance of students
knowledge test performances were obtained from an adaptive-courseware E-learning
system that administered knowledge tests to thirty, first year undergraduate students,
from two southeastern European Universities, University of split Croatia and
University of Mostar Bosnia-Herzegovina in the domain of “computer as a system”
comprising of seventy three domain concepts. The results of this knowledge test, the
students‟ scores in each of the seventy three domain concepts is to be used as crisp
inputs to the proposed fuzzy membership functions to enables the realization of the
first fuzzy logic control process, the fuzzification process. The propose membership
functions are designed using multi fuzzy terms "poor", "weak", "average", "good",
"very good" and "excellent" to allow for adequate fuzzy sets that can capture all
intervals in the distribution.
However, we need to compare the performance of the propose model with that of the
two previous or existing models. With the first model that has 36% accuracy, this
comparison is direct as it was implemented using same training data with the propose
model. But with second model that has 90% accuracy, this comparison cannot be
made directly as it was implemented using different training data with the propose
model. This study therefore re-implement the second model using the training data
from the domain of “computer as a system” in order to justify the performance of the
propose model. The result has shown that the propose method has successfully
improved the accuracies of the two previous models.
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