By Mariam Mathew

Tell me and I forget. Teach me and I remember. Involve me and I learn.
Benjamin Franklin

When I was asked to take up teaching of an Ecology module using a problem-based learning approach, I was truly looking forward to the experience. The Ecology module is part of the Diploma in Civil & Environmental Engineering at Ngee Ann Polytechnic.

As a student, I remember how I really enjoyed reading my Ecology textbook. But what registered most was the fact that theory alone can be drab. There was something about the examples in the book that really grabbed my attention − those examples were written from a West African point of view.

This gave me an idea of what my own students will enjoy and at the same time, learn from – something that is not too theory-oriented but rather case-based.

Initial Concerns about Using PBL

There were three key issues that I needed to address before using a PBL (problem-based learning) approach:

• How will I handle time pressures? I was only given 2 hours per week for the module;
• How do I switch from lecturer role to facilitator role? How do I resist the urge to just dish out the answers to questions that my students ask? After all, this is what I have been doing all these years as a teacher.
• How will I maximize learning from the student presentations? Thinking about previous experiences of group presentations brought back unpleasant memories of straining to listen as each group of students presented their results while the other students chattered their heads off. This was not something I was looking forward to with this class. How will I get through two doses of this every other week over an entire semester?

Managing the concerns

- Stretch the problem

I felt that using short, simple problems that students would be able to complete within two hours per week would not have a good learning outcome. Instead, I decided that each problem would have to run over a number of weeks in order for each problem to stretch students’ breadth of investigation and depth of thinking and analysis. The problems I eventually used were designed to run over 2 or 3 weeks.

- Switch to philosopher mode

For the second concern where I needed to adopt the “facilitator” role, I made a mental note to hold my tongue and keep reminding myself to answer every question with another question. Would I succeed at that? Frankly, I was not too sure! I was glad to find out from their reflections that I did OK!

- Showtime!

To address the third concern of getting students to listen to the presenters, I decided to tell them that I would encourage each group to ask questions of the presenting groups, to keep the monotony out.

I told them that since there would be a great deal of information in the presentations, I would be learning from it and would be noting things down. The same would apply to all of them, and since neither lectures nor lecture notes would be provided, they were responsible for extracting all the information.

They saw the logic in that.

The outcome was that the presentation sessions tended to be very lively and good fun, compared to the monotonous presentations I have seen in my other modules where the reflective process was not enforced and I left the class with a splitting headache and my spirits flagging!

Formulation of the PBL Problems

After attending a series of courses and discussions at the Teaching and Learning Centre, I felt more confident in my knowledge of the key requirements and methodologies for facilitating learning using PBL.

I asked myself what the purpose of the module would be. I decided that at the end of the semester, the students should go away with:

• An awareness of ecological disasters,
• The reasons why ecological disasters occur,
• The current state of the environment,
• The role of Ecology as a measure of the health of the environment, and
• How science and technology can be applied to solving or correcting these problems.

For almost all the problems, there was an abundance of “new” and “real” ecological disaster topics. This allowed me to formulate new problems every semester, as each species and each habitat is unique. Every group was given the freedom to choose a solution that they (as a group) agreed upon as appropriate.

There was the added bonus that such an approach reduces the chance of plagiarism.

Outline of the PBL Problems Used

Students solving a
PBL problem

1. Koala Overpopulation

There is a koala population explosion on an island off Australia. Koalas are an introduced species on this island, a nuisance there, yet an endangered species in the rest of the country − and a national icon. The choice of population control had to keep the delicate issues of tourism and animal rights in sight.

I still recall with amusement a debate in the class during a presentation in the first semester when one group suggested opening a “hunting season” for koalas to encourage tourism: the koala lovers and animal rights activists took the bait and argued, while the skeptics sniggered, and as the debate rolled on, one well-read student came up with a statement that put a stop to it all:

Who would want to shoot koalas – they are animals that move so slowly that they take half a day to move down or up a tree – what’s the thrill to a hunter – shooting slow animals and easy target is no fun.

I was really impressed with this group – I did not have to say anything else to them!

2. European Rabbits in New Zealand

In the second semester, the problem revolved around the thriving population of European rabbits, an introduced species to New Zealand.

3. Cane Toads

In the third semester, the problem statement concerned cane toads, an introduced species that became a nuisance in Australia.

In two out of the three cases mentioned above, the introduced species were brought in from elsewhere as a predator to control population of some agricultural pest, and ended up becoming a pest – this was the “catch” when introduction of predators was considered as an option.

The choice of such a topic covered a host of related topics in ecology, and helped to link these topics together in a neat manner:

• Population ecology,
• Food chain,
• Food web,
• Introduction of foreign species,
• Population control methods (the plus and the minus points of each),
• Competition,
• Extinction of species,
• Animal rights,
• Connection to economics and tourism

4. Global Warming

This topic also spanned across several topics.

A controversial solution to global warming was given. The concept was to add nutrients to parts of the oceans to encourage algae growth (the equivalent of pollution with nutrients, which elsewhere, the industry is trying to avoid!) – which would reduce carbon dioxide gas in the air during photosynthesis and in turn, feed fish (thus encourage a profitable aquaculture business as well, and feed the world’s hungry).

Students were given 3 weeks: In the first week, they would have to work on the topic of global warming and greenhouse effect, photosynthesis and geochemical cycles. In the second week, they would have to establish the efficacy of this proposed solution – to decide whether or not to support this idea. In the third week, they would present their findings and arguments.

5. Pesticides

The sub-topics that students needed to examine were:

• Pesticides – to ban or not to ban;
• Integrated Pest Management for control of Dengue fever or
• Develop a mosquito trap specific to Aedes mosquito.

The aim of a problem on these lines was to demonstrate the effectiveness and long-term effects of pesticides; holistic approaches to preventing an epidemic and application of information gathered on a particular species.

The Importance of Good Problem Writing

My conclusion from the experience was that the choice of topic and careful formulation of the problem statement played a key role in keeping their interest and increasing learning outcomes.

Workload Issues

On reflection, I decided that I would need to change and improve some of the processes so that students’ workload would be reduced. In part, this was achieved by getting the students to complete more of the tasks during class, rather than outside school time.

Also, not every lesson was devoted to solving problems. Towards the end of the semester I made use of a video on eco-tourism in class and I believe this had positive learning outcomes while reducing workload.

Using e-Learning Tools to Facilitate PBL

The PBL approach is certainly enhanced by the use of e-tools, since they help students to investigate, discuss, collaborate and present their results. Some of the e-tools that the students used were:

a. Discussion Forums

As soon as the groups were formed I would open group discussion forums on Blackboard. These forums were accessible only to the students belonging to the respective group and me, so that they can:

• Discuss the problem in private;
• Exchange information, files and pictures that they gather or prepare during their background research.

As time went by, the students tended to use various other IT tools such as MSN messenger — depending on their comfort level.

Most of the research was done online and when reflecting, they were asked to critique their sources.

b. Student-prepared Websites

One particular cohort of students had two interested groups preparing web-sites on “How Engineering can be used to Address the Challenge of Global Warming” for the Sterling Website Competition organized by the British Council (Eco-Manifesto and Green Earth). Both of these were short-listed into the final round. Students used Adobe Dreamweaver to develop the Websites.

In that particular semester, the students were asked to discuss using a Lotus Notes-based ‘green-room forum’ that was linked to the two websites.

Participants in the Sterling Website Competition

c. Use of External Forums

Later on, I used the “green-room forum” to update the class on the latest happenings in the environmental field and interesting topics. Topics discussed were: “Whimsical Solutions to reduce global warming’ and ‘Engineering Solutions to reduce global warming”.

d. Use of MS Office Tools

As a class, all groups made good use of Microsoft office tools especially Powerpoint, Excel and Word.

There were instances where the students were not using the most appropriate tool. In the very first semester, one of the students was not fully aware of MS Excel’s capabilities and he actually plotted his concept of a population model as a graph using Word’s drawing tools! While I felt it was a laudable attempt, I made sure he knew how to draw graphs using Excel…

e. Using the Library’s e-Databases

The students also got to use the e-library facilities in the Ecotourism problem. This increased their awareness of the availability of this resource.

Student Reflections

Reflection played a vital role in developing a greater awareness by the students of:

• Their learning;
• The areas that need further development;
• Their strengths; and
• Their weaknesses.

On the final day of semester, students submitted reflection forms. Included was a requirement for peer groups to comment on their degree of satisfaction with answers to the questions they posed to each of the presenting groups.

I realized that one of the key aspects to success is to convince students that the whole process of thinking, exploring, finding and presenting those solutions, and then justifying those solutions is important – even if the choice of the “solution” to the problem was not the “most appropriate”. This realization usually only dawned on them while participating in the critique of their presentation and as they reflected on their own learning journey.

One of the students wrote:

She said that the only way one could learn something is when that person is participating in the whole learning process

Feedback

Giving Feedback to Students

My observation is that the students value feedback – both from the facilitator as well as from their peers. Feedback is important especially for first-year students who might be presenting for the first time and grappling with a new method of teaching.

Once feedback is peppered with the good aspects as well as – room for improvement, no feelings are hurt, and they reflect on what they have been told, and work on the flaws for the next presentation. Normally, the earnest ones do show a marked improvement.

The PBL approach gives students much more developmental feedback on a range of learning issues, including problem analysis, quality of solution, presentation and also content learned. Feedback is also obtained from multiple sources and perspectives during the execution of a PBL learning event.

Getting Feedback from Students

Some of the feedback written by students:

“The tutor asks us questions that make us think harder, gives feedbacks on some groups presentation which make me more aware what I should do or not in future presentations”

“The feedback that she given help to point out the mistakes’”

“Telling us how to improve on the presentation – The feedbacks given”

Looking back

In retrospect, if I were to do this module again, I would ask the students to do their reflection using blogs. From recent experiences with students in another module, I find that some students who pass up mediocre submissions with pen and paper tend to do an impressive job especially when reflecting on a blog!

I also strongly feel that the use of such a module in the very first semester does play a vital role in class bonding.

By going through the problems and the process, I was confident that the students achieved the learning objectives, which were to ignite their interest in the environment, identify the role of science and technology in it, and to link the various environmental issues to ecology in an engaging manner. I also felt that the students gained by dabbling with the basic e-tools.

More importantly, by going through the reflection process, the students gained a deeper understanding of their own learning as well as gaining more insights into the ecology content that they had discovered.

By Mariam Mathew
Division of Building and Environment, School of Engineering,
Ngee Ann Polytechnic

[Koala image source (used on the home page story summary).]