5th Asia Pacific Conference on Problem-based Learning, Petaling Jaya March 16-17, 2004
A First Attempt at Problem Based Learning in Process Dynamics and Control Course
for Chemical Engineering Undergraduates at
Universiti Teknologi Malaysia
Khairiyah Mohd. Yusof1 , Mimi Haryani Hassim1 and Azila NMA2
1
Faculty of Chemical & Natural Resources Engineering, Universiti Teknologi Malaysia,
Johor Bahru
2
Faculty of Medicine, University of Malaya, Kuala Lumpur
ABSTRACT
Engineering educators are currently concerned with producing graduates who have mastery of
knowledge and generic or “soft” skills. A blend of both attributes would equip graduating
engineers with critical thinking and problem solving skills, continuous self-learning abilities,
and teamwork and communication skills. However, being burdened with heavy course
requirements that must be fulfilled within a specified time frame, teachers tend to adopt
didactic teaching approaches while students tend to rote learn what ever that has been spoonfed, which tend to produce graduates with qualities far from the desired outcome. The
million-dollar question is: how can we produce the desired quality of engineering graduates
within the restricted amount of time?
In the Faculty of Chemical and Natural Resources Engineering, Universiti Teknologi
Malaysia, Process Dynamics and Control is labelled by the undergraduate students as a
“killer” subject. The failure rate is high and the passing marks are low, no matter who teaches
the subject. The subject is considered by many to be difficult because it requires students to
combine their knowledge in chemical engineering and mathematics. Students often fail to
understand and visualize a process in operation, and relate mathematical theories to the
physical reality. As a result, most students can barely decipher the problem-solving type
questions in the exams.
In an effort to guide the students to learn and understand the subject better, as well as acquire
the necessary soft skills, cooperative learning and problem-based learning (PBL) have been
introduced. Although cooperative learning had been implemented in previous semesters, this
is the first time certain topics in the subject were covered through PBL. This is also the first
time students from this faculty are exposed to PBL. This paper describes the implementation,
feelings and thoughts of both lecturers and students, and the outcome of PBL in the Process
Dynamics and Control class.
1. INTRODUCTION
In today’s competitive global economy, engineering graduates equipped with mastery of
knowledge alone is insufficient. Industries demand that graduates should also have critical
thinking and problem solving skills, continuous self-learning abilities, and teamwork and
communication skills. Complaints from corporations regarding the lack of professional and
generic skills in engineering graduates have often been heard. This is not a local issue, but
also a global concern. As a result, from 2001 onwards, the US Accreditation Board for
Engineering and Technology requires that Engineering Schools in the US must demonstrate
that their graduates posses generic and professional skills [Rugarcia, et al., 2000].
Nevertheless, the current reality is far from what is desired. Engineering students generally
have to handle and digest a challenging amount of content within a specified period. In
Universiti Teknologi Malaysia, the standard total period of study is 8 semesters. With 14
weeks in a semester (including public holidays), all the material in the course syllabus must
5th Asia Pacific Conference on Problem-based Learning, Petaling Jaya March 16-17, 2004
be taught. Pressed for time, lecturers would adopt didactic teaching approaches, no matter
what students gain as long as the syllabus can be completed on time. Students tend to rote
learn what they have been spoon-fed with, often relying just on lecture notes to pass a course.
Adding more courses to include generic skills to an already over-loaded curriculum and
syllabus is challenging. There is also resistance, not only by the lecturers (due to time
constraints, inadequate knowledge on teaching and learning techniques, and lack of incentive)
but also students, to move away from their comfort zones [Felder, et al., 2000].
The question is how can the students develop the necessary skills and qualities while learning
to master the subject within the limited time? It is clear that the teaching and learning
approach must be changed so that the additional skills needed may be embedded in the
present syllabus. In engineering education, there has been a lot of research and application in
active learning, particularly cooperative learning, to help students learn and understand more
effectively as well as inculcate generic skills in students [Felder, et al., 2000]. Problem-based
learning (PBL), which can be a subset of cooperative learning, has also been recommended
and implemented in engineering, particularly because it promotes deep learning and problemsolving skills [Woods, 1996, Woods, et al., 2000]. However, the application of PBL in
engineering (usually subject-based) lags far behind its application in medicine (usually
curriculum-based).
This paper describes the first attempt at introducing PBL in the Process Dynamics and
Control Course for the fourth year Chemical Engineering students in Universiti Teknologi
Malaysia. This was also the first exposure to PBL for most students. The feelings and
thoughts of lecturers and students, as well as the results, are documented.
2. PROCESS DYNAMICS AND CONTROL COURSE
2.1 Description
Process Dynamics and Control is a required course for fourth year undergraduate chemical
engineering students in the Faculty of Chemical and Natural Resources Engineering,
Universiti Teknologi Malaysia. It is a three credit-hour course, which means that there are
three hours of classes per week, for 14 weeks. Three to five sections of the class are offered
each semester, with a maximum number of 60 students per section. The course is notorious
for the high number of failures (usually around 30%, sometimes as high as 45%), low passing
grades (mostly in range of 40-50%) and considered by many to be difficult. Those who fail
mentioned that they do not understand the material, and those who passed with low passing
grades indicated that they barely understood the material and did not have good understanding
of the subject.
The process dynamics and control course deals with mathematical modelling of process
dynamics, and control systems design and analysis of chemical processes. The systems that
are dealt with in the class range from simple equipment, such as storage tanks, heated tanks,
heat exchangers, and furnaces, to more complex ones such as distillation columns, reactors,
dryers and evaporators. Students need to understand and visualize a process in operation, and
relate mathematical theories to the physical reality. This is the first time they have to deal
with processes in dynamics instead of steady-state. Thus, students need a strong background
in mathematics and other chemical engineering concepts, learned earlier, to fully appreciate
the class material.
In a typical lecture-based Process Control class, students seem to understand the material, but
most fail to perform in quizzes and tests. Queries for questions are normally met with a
deafening silence. Asking questions only made students uneasy and avoid eye-contact. It is
also normal to see students nodding off to sleep, especially when the lectures are packed with
mathematical derivations and analysis. It is not surprising, therefore, to see studies reporting
5th Asia Pacific Conference on Problem-based Learning, Petaling Jaya March 16-17, 2004
that students can only recall 70% of the material presented during the first ten minutes and
20% of the material of the last ten minutes [Felder and Brent, 1994, Fraser, 2002].
This semester (2003/04 – 02), four regular sections and one section for repeaters (those who
had taken and failed the course) of the Process Control and Dynamics course were offered,
each taught by a different lecturer. Sections 2, 3 and 4, used traditional lecture style.
Sections 1 and 5 were taught using cooperative learning and PBL. Section 5 consists of weak
students, who usually have low motivation, repeating the course. All sections sit for the same
tests and final examination. All tests and examination were taken individually. All the
examination scripts in the tests and final examination were graded by the lecturer who set the
respective questions to ensure consistency in marking the exams. The breakdown of the
marks for the whole course is shown in Table 1.
Table 1 Grading breakdown for the course.
Assignments, Quizzes & Peer
Review
Test 1
Test 2
Final Exam
Percentage
20
15
15
50
To implement cooperative learning in sections 1 and 5, students were divided into groups of
four or five. They were asked to fill in a personal information form that consists of their
cumulative grade point average (CGPA), the grades obtained for the courses that were the
prerequisite of this course, and what they aim to get out of the class. For most of the students,
this was the first time that they have encountered cooperative learning. Cooperative learning
was described, and the advantages were explained. Rules and policies of the class, especially
those designed to ensure that each student contribute to the group were discussed in class. The
students were also given motivation on team work. By the end of the first week, the students
were divided into groups. The university’s academic regulation allows students to change
sections within the first few weeks of the semester. Therefore, those who were unhappy with
cooperative learning, especially those who do not want to work in groups, were allowed to
change to section one. However, students from other sections were only allowed to join this
section in the first week of class, not later.
Students were assigned to various groups according to a mixed ethnic background and
genders. Each group consists of three to five students. Students with high CGPAs were also
mixed with students with low CGPAs. As far as possible, there were at least two good
students with CGPA above 3.0 (out of 4.00 maximum), and at least two female students in a
group. The rule for grouping students was made based on recommendations published in the
literature [Allen, et al., 2001, Felder and Brent, 1994]. To develop a sense of belonging, the
students were encouraged to choose a name for their groups.
From the second week onwards, students were asked to work in their respective groups.
Quizzes and assignments were performed in groups. There were in-class assignments, as well
as out-of-class assignments. Students were reminded to contribute and at least try to work out
a rough approach to the problem for the out-of-class assignments before the formal group
discussion in class. There were three recommended text books for the course, each with its
own approach in the topics covered. Each group was advised to have at least a copy of all
three texts. The students were also encouraged to find other resources for the subject. This
was purposely done to encourage students to be resourceful and share the knowledge gained
among their group members.
5th Asia Pacific Conference on Problem-based Learning, Petaling Jaya March 16-17, 2004
2.2 Implementation of Problem-Based Learning (PBL)
PBL was implemented from the 8th to the 11th week of the semester in sections 1 and 5. Since
both sections had only one facilitator, the floating facilitator concept was used. Section 1 had
13 groups and section 5 had 8 groups. The case study, which was on a phosphate pebbles
moisture control system [Smith and Corripio, 1997], was broken down into three parts. The
case study was modified from a text that was not used in class. The first part was due at the
end of two weeks (end of week 9), the second after one week (end of week 10) and the third
after one week (end of week 11). Students were not given any lectures on the material
covered in the case study. Since most of them have never heard of PBL, they were briefed on
what PBL is, the advantages and how to approach the problem.
The case study was first given to the groups in a two-hour class. They have to understand the
process as well as identify the problem and learning issues. About mid-way through the class,
the first of two triggers for the first part of the case study was given. Students were given two
days to complete the triggers and present the answers in a one-hour class. The triggers
contain key words or concepts that would help the groups identify learning objectives and try
to solve the problem. During the first session, some students seemed flustered and puzzled.
Some groups had to be prompted to read the case study out loud, discuss and brainstorm. At
the end of the session, most felt burdened and worried that they might not be able to learn on
their own and solve the problem. In section one, a student came up to the lecturer and asked,
“I don’t understand why you’re doing this. Wouldn’t it just be easier to teach us?” In section
five, a student was heard complaining to his group mate, “Other sections have it easy – they
don’t have to do anything!” Needless to say, most students left the class with gloomy faces.
In the next one-hour class where answers to the triggers were submitted and presented orally,
the students seemed happier and more cheerful. During the presentation, it was clear that they
have managed to decipher the problem and were well on the way to solving it. Almost all
students were happy to participate in the presentation, willingly offering answers even to
questions that require deep thinking. Their enthusiasm was apparent by their willingness to
present even without being given any rewards in terms of marks.
The second
trigger/assignment, which was due in the next class, was given at the end of the class.
There was obvious relief and satisfaction when the groups handed in the first part of the case
study. The result of the case study was also orally presented by students and discussed in
class. In their learning journal, most students had remarked that they have been pleasantly
surprised by the turn of events. Almost all had reported anxiety right after receiving the case
study. Now that they have managed to solve the problem, they really appreciate the
knowledge that they have gained. Some reported that they have discovered new things about
themselves. One student remarked, “I never knew I could read three chapters in one night!”
Many of the students praised their group mates. Nevertheless, there were some who remarked
that they disliked the method because it’s too time consuming (“Every day is control day – I
have other subjects too!”). There were also students who doubt that the topic had been well
covered by the case study, and that they would not be able to answer questions in the exam.
The second and subsequently the third part of the case studies went smoothly. They are
shorter, and each part had a one week duration. Each part had one assignment to be submitted
and presented. The students were obviously more confident than the earlier discussion
encounters, and some were actually enjoying themselves. One student noted in her learning
journal, “I’ve never been in a class where everyone is so eager to answer questions.” Another
student wrote, “I have never felt sleepy in this class – and this is an 8:00 am class!” In section
5, which was the section with weak students, attendance shot up to almost 100% when PBL
was implemented, compared to just 50% before PBL. Since everyone must contribute to the
group, the group members would actually call each other up to ensure that all would be
present, especially for 8:00 am classes!
5th Asia Pacific Conference on Problem-based Learning, Petaling Jaya March 16-17, 2004
3. OUTCOME, RESULTS AND DISCUSSION
3.1 Response To Questionnaires On PBL
Students in both sections were given a questionnaire to fill in at the end of the third part of the
case study. The results are summarised in Table 2. Questions are listed in the first column,
and the percentage of students giving positive and negative response for sections 1 and 5 (ie.
S1 and S5) are tabulated in the respective columns. Those who gave both positive and
negative response, or those who were undecided, are grouped under the “Undecided” columns
for S1 and S5.
Referring to Table 2, the students, on the whole, view PBL positively. It is interesting to note
that although the percentage of those who are totally positive about PBL is not very high, the
percentage of students who would recommend that other subjects use PBL and would like to
attend more classes with PBL is very high (nearly 100%). This is because even though some
students were undecided, they would still recommend PBL and realise that they can benefit
from PBL.
The students who liked PBL commented that PBL made the subject more interesting,
generating a happy and conducive environment for learning. They enjoy “cracking their
brains” to meet the challenge of solving the problem, and actually appreciate the knowledge
gained. Some were even relieved that PBL stopped the spoon-feeding culture. Many of them
noted that they learned more systematically, and were better prepared for class. The students
also obviously benefited from their groups. They found the group discussions helpful, and
were able to gain better understanding from explaining to and arguing with their group
members. Some students felt that the quest for information to fill in the knowledge gap to
solve the problem provided motivation for them to think and learn, not only for the sake of
examinations. Those who did not like PBL had stated similar reasons: there was too much
work involved in the active learning approach, which depletes their time for other subjects.
They also disliked free-riders.
Table 2. Results of questionnaire.
Questions posed (simplified)
Positive
S1 S5
Negative
S5
S5
Undecided
S1
S5
What do you feel about PBL?
65
75
8
2
33
17
Learned more in PBL compared to traditional
lecture?
Recommend PBL in other subjects?
73
79
17
13
10
8
96
96
4
4
0
0
Attend another course using PBL?
95
94
0
6
5
0
Problem-solving ability increased?
76
96
15
4
9
0
Self-learning and motivation increased?
87
96
7
4
6
0
Interaction and team-work skills increased?
89
100
7
0
4
0
Self-confidence increased?
70
84
18
8
12
8
5th Asia Pacific Conference on Problem-based Learning, Petaling Jaya March 16-17, 2004
73% and 79% of students from sections 1 and 5 respectively responded that they learned more
with PBL compared to traditional lecture. An astounding number mentioned that they felt
sleepy, bored and lose concentration in traditional classes, and thus were unable to grasp most
of what was lectured. Students who felt that they learned more in lecture-based classes noted
that it depends on a person’s attitude and sense of responsibility. A lot also depends on how
well a lecturer can teach, and if assignments were given.
Most students felt that PBL increased their problem-solving abilities, self-learning and
motivation for learning, interaction and teamwork skills, and self-confidence. Some students,
who tended to be reserved, claimed that they had become vocal and defended their opinion in
group discussions. They were not afraid to offer their view even if their idea might be wrong.
Consequently, they did not feel shy to speak-up in class anymore. Students also noted that
they were able to learn how to tolerate and accept differences, communicate with different
people, and had made good new friends, even among different races. Many reported that they
felt motivated to learn because they felt responsible towards their group to help solve the
problem and contribute in discussions. 70% and 84% from sections 1 and 5 respectively
responded that PBL increased their confidence. They felt more confident to present, and face
the examinations.
Comparing sections 1 and 5, it is interesting to note that the percentages of positive response
for an increase in the stated abilities are higher for section 5, which is the class with weaker
students. This difference in response may be because some students in section 1 felt that they
already have the confidence, motivation, and problem-solving and communication skills.
Therefore, they felt PBL did not make much of a difference in improving these abilities. The
weaker students in section 5, on the other hand, felt that they have gained a lot from PBL. It
is normal to find students with low self-esteem and low motivation in repeat classes. They
usually have difficulty in understanding complex concepts taught in lecture-based Process
Control classes. The normal percentage of failure for repeat classes was at least 50%, and
sometimes as high as 70%. With PBL, these students were able to understand better by
actively discussing and doing assignments with their team mates and adopting a more positive
attitude. Some students even called up their team mates in the morning to wake them up for
8:00 am classes. Having others rely on them, and the desire to complete the case study,
provided the much needed motivation to learn on their own. All these, in turn, increased their
self-confidence. These positive changes in outcomes and attitude were also noted in other
studies (Polanco et al 2001).
3.2 Test Results
A week after completing the case study, students from all sections were assessed in Test 2.
Question 2 in the test was on the topics covered in the case study. The lecturer who set the
question also marked the question for students from all sections. The question should be
manageable for all students as it was similar to an example in one of the recommended texts,
except for the difference in the process. Figure 1 shows the marks distribution of students
from all five sections of the course. S1, S2, S3, S4 and S5 refer to sections 1, 2, 3, 4 and 5
respectively. The average for sections 1, 2, 3, 4 and 5 were 20.25, 10.85, 9.3, 5.15 and 13.76
respectively. The total marks for Question 2 was 33.
With reference to Figure 1, students in section 1 performed the best among all sections (the
lecturer for section 1 did not set the question nor marked the answer scripts). More than 60%
of the students in section 1 scored above 20 for the question. The average for section 1,
20.25, is about twice of the highest average for lecture-based classes. Only about 5% of the
students in section 1 scored below 4 (nobody had 0).
5th Asia Pacific Conference on Problem-based Learning, Petaling Jaya March 16-17, 2004
Percentage of Students
70
60
S1
S2
S3
50
40
30
S4
S5
20
10
0
0-4
5-9
10-14
15-19
20-24
25-30
Above
30
Distribution of Marks
Figure 1. Distribution of marks on question 2 for Test 2.
The performance of the students in section 5 was a pleasant surprise. Although most of their
marks were clustered around 5 to 15, more than 40% of the students in section 5 scored higher
than 15, and only about 5% scored less than 4. With an average of 13.76, the students’
performance was better than the lecture-based sections.
3.3 Lecturer’s Reflections
The lecturer in section 1 is an experienced lecturer, with more than 10 years of service, while
the lecturer in section 5 is young, with nearly 2 years of teaching experience. Both lecturers
had attended PBL workshops in the university, and were enthusiastic about implementing the
technique in class. The young lecturer, however, was not really confident that the coverage of
the case study would be thorough. Furthermore, the students in section 5 were weak students
with low motivation. The lecturer was therefore worried that they might not cooperate, fail to
understand on their own, and cannot answer the case study at all.
During and immediately after the first class when the case study was given, both lecturers felt
anxious because of the somewhat negative reception from the students. To make matters
worse, the teaching evaluation forms were distributed and filled in by the students at about the
same time. They wondered whether they would be evaluated badly and whether it was worthy
for the sake of student learning and PBL.
Both lecturers were pleasantly surprised that the students were receptive and positive towards
the case study during the first task presentation. The students were clearly able to understand
the material, and even more. Doubts about the teaching and learning technique vanished,
although both still felt that their facilitation skills need to be brushed up. The positive
response from the students gave both lecturers motivation to continue on with the second and
third parts of the case study.
After completing the third part of the case study, both lecturers were happy with the students’
cooperation, and pleased that most students, even the weak ones, showed positive outcome.
5th Asia Pacific Conference on Problem-based Learning, Petaling Jaya March 16-17, 2004
After looking at the results of the first test, the lecturers were even more pleased because of
the students’ improved performance.
4. CONCLUSION
The first attempt at introducing PBL in some topics of the Process Dynamics and Control
course were initially met with doubts both on the part of lecturers and students, especially as
to whether PBL could be effective in improving learning. However, it did not take long
before PBL was well-received by most students as indicated by the change in learning attitude
and the performance of students from both sections as compared to the lecture-based classes.
This shows that the topics covered by the case study were better understood with PBL
compared to traditional lecture delivery approach.
Although no exact measurement was made, from the lecturers’ observations and the
questionnaire filled in by students at the end of PBL implementation, most students had
gained important learning and problem solving skills, as well as interaction, teamwork and
communication skills. The improvement in learning and problem-solving skills was
especially evident in weaker students as shown in the survey, and the test results.
The implementation of PBL is still far from perfect. Both lecturers plan to design more cases
for the course in the coming semester. Nevertheless, both do not want to rush, preferring to
take it one step at a time, as recommended by Woods, et al.[2000]. It may still be a few
semesters yet before PBL is fully implemented in the whole course. However, this first trial
run on PBL convinced both lecturers of the benefits of PBL, and thus increased the
commitment of both in its implementation. Seeing the students flourish and gain not only in
terms of mastery of knowledge, but also generic and professional skills, was definitely worth
facing their initial wrath!
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