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Development of a diagnostic system using a testing-based approach for strengthening student prior knowledge
Computers & Education (September 2011)
Yi-Chun Lin, Yen-Ting Lin, Yueh-Min Huang*Department of Engineering Science, National Cheng Kung University
Introduction
Assist instructors in diagnosing and strengthening students’ prior knowledge before new instructions and to enable students to attain greater learning motivation and improved learning performance
A testing-based diagnosis system is proposed in this study to cope with these problems
Methodology
To measure the strength of understanding of prior knowledge
Prior knowledge diagnosis (PKD) model is proposed
Two data sources: Testing information assigned by teachers
Testing information derived by students
Represents a relationship between each concept and test item in a test, and the relationships among the concepts
Represents a relationship between student’s answers and the test items
Methodology
A course specifies n concepts C1, C2, C3,…, Ci,… Cm,…, Cn
Prior knowledge of the subject for r participating students S1, S2, S3,…, Sl,…, Sr
Teacher select k test items from the test item bank to form the pre-test T1, T2, T3,…, Tj,…, Tk
Methodology
Xmj indicates the degree of relevance between the m-th concept and the j-th test item represent the degree of relevance between
each concept and test itemZim indicates the relationship between
the ith and the mth concepts(ranged from 0 to 1) represent the relationship between the
concepts
Methodology - Strength of concept
The strength of concept Ci in the pre-test
Zim represents the relationship between the i-th and the m-th concepts, 0 ≤ Zim ≤ 1
Xmj indicates the degree of relevance between the m-th concept and the j-th test item, 0 ≤ Xmj ≤ 1
0 ≤ S(Ci) ≤ nk
Methodology - Importance ratio of concept
The importance ratio of concept Ci in the pre-test
Zim represents the relationship between the i-th and m-th concepts, 0 ≤ Zim ≤ 1
Xmj indicates the relevance degree between the m-th concept and the j-th test item, 0 ≤ Xmj ≤ 1
0 ≤ IRP(Ci) ≤ 1
Methodology - Understanding strength of the lth student
The understanding strength of the lth student on the ith concept
Rlj indicates the answer of the l-th student on the j-th test item• If the student answers the test item correctly,
Rlj is 1; otherwise Rlj is 0
Zim represents the relationship between the i-th and the m-th concepts
Xmj indicates the degree of relevance between the m-th concept and the j-th test item
Methodology - Understanding strength of the concept
Translate the importance ratio of the concept into the understanding strength of the concept
To t(Ci) represents the threshold value of the i-th concept, 0 ≤ t(Ci) ≤ 1
m indicates the gradient of the function, m = 1 IRP(Ci) represents the importance ratio of
concept Ci in the pre-test, 0 ≤ IRP(Ci) ≤ 1
b is the point at which the line crosses the y-axis, b = 0
Illustrative example
Test item Concept
C1 C2 C3 C4 C5
T1 1 0 0 0 0
T2 0.2 0 0.6 0 0.2
T3 0 1 0 0 0
T4 0 0.4 0 0 0.4
T5 0 0 0 0.2 0
Illustrative example of relationship between test items and concepts
Illustrative example
Concept Concept
C1 C2 C3 C4 C5
C1 1 0 0.4 0 0
C2 0 1 0.6 0 0.2
C3 0.4 0.6 1 0.2 0.6
C4 0 0 0.2 1 0.4
C5 0 0.2 0.6 0.4 1
Illustrative example of relationship between concepts
Strength of Concept
The strength of the first concept (C1): S(C1) = Z11 *X11 + Z11 * X12 + Z13 * X32
= 1.0 × 1.0 + 1.0 × 0.2 + 0.4 × 0.6 = 1.44
S(C2) = Z21 *X23 + Z21 * X24 + Z23 * X32 + Z25 * X52 + Z25 * X54
= 1.0*1.0 + 1.0*0.4 + 0.6*0.6 + 0.2*0.2 + 0.2*0.4 = 1.88
Test item
Concept
C1 C2 C3 C4 C5
T1 1 0 0 0 0
T2 0.2 0 0.6 0 0.2
T3 0 1 0 0 0
T4 0 0.4 0 0 0.4
T5 0 0 0 0.2 0
ConceptConcept
C1 C2 C3 C4 C5
C1 1 0 0.4 0 0
C2 0 1 0.6 0 0.2
C3 0.4 0.6 1 0.2 0.6
C4 0 0 0.2 1 0.4
C5 0 0.2 0.6 0.4 1
Importance Ratio of Concept
Importance ratio of concept
Concept
C1 C2 C3 C4 C5
IPR 0.19 0.25 0.31 0.07 0.18
The importance ratio of second concept (C2)
IRP(C2) = 1.88 / 7.52 = 0.25
Illustrative example
Test itemStudent
S1 S2 S3 S4 S5
T1 1 1 0 1 1
T2 1 0 1 1 1
T3 0 0 0 0 1
T4 0 1 0 1 1
T5 0 0 1 0 0
Illustrative example of the relationship between students’ answers and test items
Relationship between students’ answers and
test items (R)
Illustrative example
StudentConcept
C1 C2 C3 C4 C5
S1 1 0.21 0.52 0.36 0.42
S2 0.69 0.26 0.38 0.29 0.36
S3 0.31 0.21 0.36 0.71 0.48
S4 1 0.47 0.72 0.64 0.79
S5 1 1 0.98 0.64 0.94
Relationship between students’ understanding
strength and concepts (USS)
Test item
Student
S1 S2 S3 S4 S5
I1 1 1 0 1 1
I2 1 0 1 1 1
I3 0 0 0 0 1
I4 0 1 0 1 1
I5 0 0 1 0 0
USS(S4,C5) = = = = 0.79
Test item
Concept
C1 C2 C3 C4 C5
I1 1 0 0 0 0
I2 0.2 0 0.6 0 0.2
I3 0 1 0 0 0
I4 0 0.4 0 0 0.4
I5 0 0 0 0.2 0
ConceptConcept
C1 C2 C3 C4 C5
C1 1 0 0.4 0 0
C2 0 1 0.6 0 0.2
C3 0.4 0.6 1 0.2 0.6
C4 0 0 0.2 1 0.4
C5 0 0.2 0.6 0.4 1
Relationship between concepts (Z)Relationship between test items and
concepts (X)
R41Z51X11 R41Z52X21 R41Z53X31 R41Z54X41 R41Z55X51
R42Z51X12 R42Z52X22 R42Z53X32 R42Z54X42 R42Z55X52
R43Z51X13 R43Z52X23 R43Z53X33 R43Z54X43 R43Z55X53
R44Z51X14 R44Z52X24 R44Z53X34 R44Z54X44 R44Z55X54
R45Z51X15 R45Z52X25 R45Z53X35 R45Z54X45 R45Z55X55
1.0 x 0.0 x 1.0 1.0 x 0.2 x 0.0 1.0 x 0.6 x 0.0 1.0 x 0.4 x 0.0 1.0 x 1.0 x 0.0
1.0 x 0.0 x 0.2 1.0 x 0.2 x 0.0 1.0 x 0.6 x 0.6 1.0 x 0.4 x 0.0 1.0 x 1.0 x 0.2
1.0 x 0.0 x 0.0 1.0 x 0.2 x 1.0 1.0 x 0.6 x 0.0 1.0 x 0.4 x 0.0 1.0 x 1.0 x 0.0
1.0 x 0.0 x 0.0 1.0 x 0.2 x 0.4 1.0 x 0.6 x 0.0 1.0 x 0.4 x 0.0 1.0 x 1.0 x 0.4
1.0 x 0.0 x 0.0 1.0 x 0.2 x 0.0 1.0 x 0.6 x 0.0 1.0 x 0.4 x 0.2 1.0 x 1.0 x 0.0
1.0 x 0.0 x 1.0 1.0 x 0.2 x 0.0 1.0 x 0.6 x 0.0 1.0 x 0.4 x 0.0 1.0 x 1.0 x 0.0
1.0 x 0.0 x 0.2 1.0 x 0.2 x 0.0 1.0 x 0.6 x 0.6 1.0 x 0.4 x 0.0 1.0 x 1.0 x 0.2
0.0 x 0.0 x 0.0 0.0 x 0.2 x 1.0 0.0 x 0.6 x 0.0 0.0 x 0.4 x 0.0 0.0 x 1.0 x 0.0
1.0 x 0.0 x 0.0 1.0 x 0.2 x 0.4 1.0 x 0.6 x 0.0 1.0 x 0.4 x 0.0 1.0 x 1.0 x 0.4
0.0 x 0.0 x 0.0 0.0 x 0.2 x 0.0 0.0 x 0.6 x 0.0 0.0 x 0.4 x 0.2 0.0 x 1.0 x 0.0
Illustrative example
Threshold value of concept Concept
C1 C2 C3 C4 C5
IPR 0.19 0.25 0.31 0.07 0.18
*m = 1, b = 0 for threshold function in this case
PKT&D System Architecture
Experiment
Participants : A course instructor 80 university students
Course: bioinformaticsGroup:
Control group: 40 students (used the PKT&D system)
Experiment group: 40 students (did not use the PKT&D system)
Experiment
Subject: sequence analysis approaches and tools
Concepts in prior knowledge: sequence characteristics and structures, statistical hypothesis testing, and formula expression format
Unit Instruction activities Time (min)
Understanding the importance of similarity
1. A series of guided questions (5)
2. Slide presentation (15)3. Discussions (10)
30
Introduction to the most popular data-mining tool: BLAST
1. A series of guided questions (5)
2. Slide presentation (15)3. Practice (10)
30
BLASTing protein sequences
1. A series of guided questions (5)
2. Slide presentation (10)3. Practice (15)
30
Understanding BLAST output1. Slide presentation (15)2. Discussions (15)
30
BLASTing DNA sequences
1. A series of guided questions (5)
2. Slide presentation (10)3. Practice(15)
30
The BLAST way of doing things1. Slide presentation (15)2. Practice (15)
30
Experiment Process
The learning motivation post-test score between the two groups
GroupNumber of students
Mean S.D.Adjusted
meanF(1, 77) P-value
Experimental group
40 46.45 3.42 46.411 16.340 .00*
Control group
40 41.05 7.59 41.086
Total number of students
80 43.75 6.38
To measure the students’ learning motivation, Motivated Strategies for Learning Questionnaire was adopted in this study. using nine questionnaire items and a seven-point
Likert scale
The paired t-test results of learning motivation for the two groups of students
Group Tests N Mean S.D. t(39)
Experimental group
Pre-test 40 34.85 4.451 -9.688*
Post-test 40 46.45 3.425
Control group
Pre-test 40 33.1 9.072 -3.074*
Post-test 40 41.05 7.591
Students’ attitude towards bioinformatics learning
# ItemExperiment
Group (Mean, S.D.)
Control Group (Mean, S.D.)
t-value
1 I like learning bioinformatics 5.45/0.87 5.05/1.08 1.82
2The bioinformatics learning activities are helpful
5.68/0.76 5.35/0.83 1.82
3I like to practice using the software in the bioinformatics learning
5.75/0.87 5.53/0.88 1.15
4I had enough ability to learn the bioinformatics material
5.28/0.99 4.38/1.44 3.25*
5I can meet the instructor’s requirements during the bioinformatics learning process
5.38/0.90 4.40/1.52 3.50*
6I can understand the bioinformatics material taught by the instructor
5.45/0.85 4.55/1.55 3.22*
Experiment group students’ perceptions of using the PKT&D system
# Question EU(%) QU(%) SU(%) Neither(%) SL(%) QL(%) EL(%) Mean
1
Using the PKT&D system in learning bioinformatics would enable me to diagnoseand strengthen prior knowledge more effectively
0 5 7.5 5 27.5 32.5 22.5 5.43
2Using the PKT&D system would improve my bioinformatics learning performance
0 0 5 20 30 30 15 5.30
3
Using the PKT&D system in learning bioinformatics would increase my learningcomprehension productivity
0 0 2.5 12.5 42.5 30 12.5 5.38
4Using the PKT&D system would make it easier to learn bioinformatics
0 2.5 7.5 10 37.5 37.5 5 5.15
5I would find the PKT&D system useful in the bioinformatics class
0 0 0 10 42.5 35 12.5 5.50
Note: EU: Extremely Unlikely; QU: Quite Unlikely; SU: Slightly Unlikely; SL: Slightly Likely; QL: Quite Likely; EL: Extremely Likely.
Independent pre-test on knowledge of bioinformatics of the two groups
Variable
Pre-test
t-valueN Mean S.D.
Experiment group 40 50.25 14.32 -0.385
Control group 40 51.50 14.77
The paired t-test results of the learning improvement for the two groups
Group Tests N Mean S.D. t-value
Experimental group
Pre-test 40 50.25 14.23 -8.460*
Post-test 40 69.50 11.54
Control group
Pre-test 40 51.50 14.77 -9.595*
Post-test 40 63.50 13.12
*p<0.05.
Independent Post-test on knowledge of bioinformatics of the two groups
Variable
Post-test
t-valueNumber of students
Mean S.D.
Experimental group
40 69.50 11.54 2.172*
Control group 40 63.50 13.12
Example interview comments about the three topics
Inductivetopics Perspectives Interviewees Transcript sample of interview comments
InstructionRealization of
studentsIN
I felt that the students in the experiment group better met my requirements during the course.
Achievement of students
INI felt that the students in the experiment group demonstrated high performance in each learning activity.
Progress of instruction
INI had much more time to teach the concepts in more detail and interact with the students of experiment group.
Learning situation INOnly one third of the students from the control group could fully follow the activities and understand my instructions.
SC & SELearning about bioinformatics software through practicing using it was interesting. I would have preferred more direct instruction from the course instructor.
SCI felt some of the concepts were difficult to grasp, which led to obstacles when I used the software during the course.
InteractionDiscussion willingness
INThe students in the experiment group had better discussions than the control group.
Responsiveness of students
INThe students in the experiment group often gave feedback and asked questions.
TechnologySystem
usefulnessSE
I felt the user interface of the PKT&D system was clear, straightforward, and convenient to use. .I clearly saw the diagnostic results and learning suggestions.
Auxiliary components
IN & SEI felt that the PKT&D system served as a guide that helps the students to diagnose the weakness of their concepts. I can learn more prior knowledge using the PKT&D system.
Evaluation of correctness rate results for the three concepts diagnosis
Evaluation of correctness rate results for the three concepts diagnosis
represents the correctness rate of the diagnoses derived from the PKT&D system,
𝐶𝑅=𝑛−(𝑛−𝑚)
𝑛×100%
Evaluation of correctness rate results for the three concepts diagnosis
Student ID 1 2 3 4 5 6 7 8
Correctness rate of
diagnoses
Expert 1 100% 100% 100% 66.60% 100% 100% 100% 100%
Expert 2 100% 66.60% 100% 66.60% 100% 100% 100% 100%
Student ID 9 10 11 12 13 14 15 16
Correctness rate of
diagnoses
Expert 1 66.60% 100% 66.60% 100% 100% 100% 100% 100%
Expert 2 100% 100% 33.30% 100% 100% 100% 100% 100%
Student ID 17 18 19 20 21 22 23 24
Correctness rate of
diagnoses
Expert 1 100% 100% 100% 100% 100% 100% 100% 100%
Expert 2 100% 100% 100% 100% 66.60% 100% 100% 100%
Student ID 25 26 27 28 29 30 31 32
Correctness rate of
diagnoses
Expert 1 100% 66.60% 33.30% 100% 100% 100% 100% 66.60%
Expert 2 100% 100% 100% 100% 66.60% 100% 100% 100%
Student ID 33 34 35 36 37 38 39 40
Correctness rate of
diagnoses
Expert 1 100% 100% 100% 33.30% 100% 33.30% 100% 100%
Expert 2 100% 100% 100% 100% 100% 33.30% 100% 100%
Evaluation of correctness rate results for the five concepts diagnosis
Student ID 1 2 3 4 5 6 7 8
Correctness rate of
diagnoses
Expert 1 80% 100% 100% 80% 100% 100% 80% 100%
Expert 2 100% 100% 100% 100% 100% 100% 80% 100%
Student ID 9 10 11 12 13 14 15 16
Correctness rate of
diagnoses
Expert 1 100% 100% 100% 80% 100% 80% 100% 60%
Expert 2 100% 100% 100% 100% 100% 80% 100% 40%
Student ID 17 18 19 20 21 22 23 24
Correctness rate of
diagnoses
Expert 1 100% 60% 100% 60% 100% 100% 100% 100%
Expert 2 60% 40% 80% 60% 100% 80% 100% 100%
Student ID 25 26 27 28 29 30 31 32
Correctness rate of
diagnoses
Expert 1 40% 80% 100% 100% 100% 100% 100% 100%
Expert 2 100% 80% 100% 100% 80% 100% 100% 100%
Note: Correctness rate obtained by comparing the diagnoses of the experts with those obtained using the proposed approach to artificial intelligence course. The average correctness rates are 90.625% and 90% for the students.
Conclusion & Discussion
Propose a testing-based approach to diagnose the strength of individual students’ prior knowledge of concepts, and then provide them with appropriate materials to strengthen this
Provide instructors can undertake their teaching more smoothly
Educators can use the proposed system in different educational contexts
Limitation
Two variables of the linear function have to be adjusted based on instructors’ expertise in different educational contexts
Future Work
The number of test items in the item bank should be continually increased to address various subject objectives and the instructors’ needs
Students’ learning portfolio can be integrated into the proposed system to develop more appropriate diagnosis mechanisms