Problems, Pedagogy and Problem–Based Learning
Problems, Pedagogy and Problem–Based Learning
Problems, Pedagogy and Problem–Based Learning
In a life science class, a teacher begins a lesson by posing a problem scenario:
How is it that when an apple drops on the floor some parts of it get damaged and turn brown? Why is that an orange does not turn brown when it is similarly hit?
The students' curiosity is further aroused when told that some 80 years ago a scientist asked a similar question: Why does a banana turn brown when it is hit? They are told that the scientist became so fascinated with and so immersed in the “banana problem” that he eventually won a Nobel Prize!
The teacher proceeds to give hints and questions for discussion that lead to the content to be learnt. The students eventually obtain several sources of references and find the information and solution to the problem.
The scientist was a Hungarian named Albert Szent-Gyorgyi. To solve the problem, Szent-Gyorgyi reasoned by comparing, classifying, observing and connecting key information in biology and chemistry. He came up with the idea that there are two categories of plants: those that turn brown on being damaged and those that do not. The fact is that plants have compounds called polyphenols. When plant or fruit tissues are damaged, the polyphenols react with oxygen to form the brown or black colour. Szent-Gyorgyi discovered that fruits like oranges contain rather large amounts of a certain sugar-like compound. He succeeded in isolating this compound, which he named ascorbic acid (vitamin C). The presence of vitamin C prevents oxygen from oxidizing the polyphenols into brown compounds. Dr Szent-Gyorgyi's work on the biological combustion processes pertaining to vitamin C won him the Nobel Prize in Physiology and Medical Science.
Problems can engage curiosity, inquiry and thinking in meaningful and powerful ways. Education needs a new perspective of searching for problems and looking at problems.
A story was told about a group of researchers working in a cornfield near Cornell University. It was a genetic experiment about the sterility of pollen from corn. The researchers observed discrepancies from what was expected, but most did not bother. A lady amongst them named Barbara McClintock decided to take ownership of the problem. In those days very few people were interested in the study of chromosomes, their genetic content and expressions (what is known today as cytogenetics). Decades later McClintock said: “When you suddenly see the problem, something happens.” Her immersion in the problem led to an insight about mobile genetic elements—a discovery that is recognized today as the bedrock of life sciences. The story took place in the 1930s and McClintock was awarded the Nobel Prize in 1983.
In education, we need to learn more from the legacy of scientific discoveries. The ability to see a problem from a mass of information, learning to make observations and connections, and the attitude of taking ownership of problems are important aspects of learning and thinking.
Sometimes immersion in a problem leads to spin-off discoveries. At a Stanford alumni gathering in Singapore, Professor Douglas Osheroff shared with us how his work led to the discovery that won the Nobel Prize. Osheroff was then a graduate student of David Lee and Robert Richardson at Cornell University. At that time they were looking for “a phase transition to a kind of magnetic order in frozen helium-3 ice”, but being immersed in the problem resulted in his observation and insight that brought about the discovery of a different phenomenon: the superfluidity of helium-3. The breakthrough in low-temperature physics won the team the 1996 Nobel Prize in Physics.
Think of the Japanese engineer who, whilst taking a walk in the park, contemplated how one could combine outdoor exercise, enjoyment of music and appreciation of nature all at the same time. His preoccupation with this problem led to the invention of tiny stereo and headphones—the Walkman.
When working as a consultant with Philips Electronics on enhancing the innovativeness of one of its most successful division—development of domestic appliances—I had the opportunity to interact with many scientists and engineers working on a variety of pre-development ideas and projects. When I spoke to their most innovative people (based on data provided by their management staff on who were some of their most inventive personnel), I found that their engagement with problems was somewhat different from that of the average research engineer. They demonstrated a special motivation, holistic involvement and abilities to harness resources and intelligences. They knew how to generate ideas, to be divergent in their thinking and at the same time be analytical and systematic. They used analogical thinking, saw the big picture and were able to bring ideas into fruition. They knew what to connect to and when and how to connect. They also did not work in isolation; they knew how to collaborate.
The challenge for education is to develop the kinds of thinking skills I have just described. Multinational corporations and organizations are seeking people with such competencies. According to International Business Machines (IBM), the people they hire must possess the following competencies: problem-solving ability, teamwork spirit, interpersonal skills, creativity, project management skills and a systems perspective.
Breakthroughs in science and technology are often the result of fascination with problems. Great learning often begins with preoccupation with a problem, followed by taking ownership of the problem and harnessing of multiple dimensions of thinking .
Problems and the questions associated with them when strategically posed can enhance the depth and quality of thinking. What is often lacking in education today is the effective use of inquiry and problem-based learning approaches .
It is not difficult to imagine that in the life science class described earlier, instead of posing a problem scenario, the teacher simply presents some facts of biology or chemistry on the topic. The opportunities to stimulate curiosity, inquiry, engagement and motivation in learning would be drastically reduced if not lost. We may not necessarily be teaching the brightest cohort of students. We are not talking about producing top-league Nobel Prize—winning scientists either. The examples cited earlier are meant to illustrate and to inspire us to take a fresh look at problems. In the ordinary classroom, the value of using problems to stimulate learning can never be overemphasized.
Many education systems are characterized by a structure of learning as shown in Figure 2.1. Learning in schools and even universities can be characterized as:
- learning by memorization
- learning by imitation
- learning by modelling
Learning by memorization begins in preschool and continues all the way to college education with a prevalence of information accumulation and knowledge recall. The predominance of paper-and-pencil testing and examinations also contributed to this mode of learning.
The kinds of so-called “problems” that students solve in many of our classes are actually exercises rather than problems. Teachers typically present in class a large number of examples accompanied by comprehensive guidelines and step-by-step solutions. Students are then given similar exercises of a variety of challenges. Often there is very little element of novelty, although these “problems” may call for synthesis and application of the knowledge learnt.
There is nothing wrong with such an approach as we need such a structured and organized approach for acquiring fundamental knowledge and foundations. These are important in establishing basic axioms, definitions and principles, particularly in disciplines like mathematics, language or basic sciences. There is, however, an overdependence on learning through worked examples and routine exercises. As a result, there is very limited use of the power of problems.
One should note that when to pose a problem and what should be the scope of the problem have in the past been limited by the learner's lack of accessibility to information. The Internet revolution has
redefined the role of educators and ushered in new possibilities in the use of problems.
For simplicity, we may classify the types of problems along a continuum of routine versus novel and artificiality versus the real world as shown in Figure 2.2. Most problems in schools would be categorized into the lower left quadrant. These routine—artificial problems are your homework exercises and examination-type questions. Sometimes we have more challenge and complexity in these artificial problems, which could be referred to as puzzles.
Lee Shulman (1991) observed that Jerome Bruner in his essay “The Art of Discovery” cited an English philosopher Weldon who used an aphorism about three kinds of challenges in this world. They are troubles, puzzles and problems:
- Troubles are unformed, inchoate, and terribly hard to focus and manage.
- Puzzles are well structured, neat and artificial.
- When you have a puzzle to place on your trouble, that is when you have a problem to work on.
According to Professor Shulman (1991) of Stanford:
Education is a process of helping people develop capacities to learn how to connect their troubles with useful puzzles to form problems. Educators fail most miserably when they fail to see that the only justification for learning to do puzzles is when they relate to troubles. When the puzzles take on a life of their own—problem sets employing mindless algorithms, lists of names … definitions—they cease to represent education. The puzzles become disconnected from troubles and remain mere puzzles. We may refer to them as problems, but that is a form of word magic, for they are not real problems (p. 2).
What Weldon, Bruner and Shulman alluded to as troubles are what we refer to as real-world problems. Problem-based learning (PBL) is about learning to solve problems in the novel—real world quadrant in Figure 2.2.
We mentioned earlier that we are not discounting learning by memorization and imitation. Similarly, learning by modelling has its merits. Indeed, the human brain and its memory system have much to gain from such systematic learning.
In many education systems, students somehow develop a tendency to think that there is a single correct answer to any one problem. In fact, Evans and colleagues (2002) found that people have a tendency to focus on a single hypothesis in problem-solving situations. In the classroom, learning by modelling often brings with it an overreliance on so-called experts. Whilst we need to model from certain expertise, what is often missing is the creative use of real-world problems. The way modelling is done often results in rather narrow, compartmentalized and inflexible systems of thinking. This problem is accentuated by the tendency towards episodic and narrow perspectives as well as unwarranted constraints of worldviews.
In Chapter 1, we reflected on the changes around us. The problems confronting the world and individuals will come with increasing rapidity, complexity and diversity. Corollaries include:
In solving real-world problems, we need to realize that a whole range of cognitive processes and mental activities are involved. The mind has to go through cycles and iterations of systematic, systemic, generative, analytical and divergent thinking .
- problems of increasing quantity and difficulty
- newer problems and shorter time frame for solutions
- more global (larger-scale) problems requiring integrated solutions
Following the Industrial Revolution, for a variety of reasons, specialization was developed to expedite the solution of problems. The socioeconomic developments also required education to accelerate the process of producing experts in specialized fields.
The 21st century, however, will be characterized by enhanced connectivity. This means that reality cannot be easily divided. Real-world issues are cross-disciplinary and involve multiple perspectives. We will need a helicopter view of things and the synthesis of a diversity of interrelated knowledge bases.
As the National Research Council (1999) of the US National Academy of Sciences noted: “The quest to understand human learning has, in the past four decades, undergone dramatic change. Once a matter for philosophical argument, the workings of the mind and brain are now subject to powerful research tools. From that research, a science of learning is emerging” (p. 5). Research on memory and knowledge, for example, points to the importance of memory not only as associations but more importantly as connections and meaningful coherent structures. We now know more about “novice” learners and “expert” learners. We can develop better learning in individuals by providing opportunities for acquisition of procedures and skills through dealing with information in a problem space and learning of general strategies of problem solving. Instead of traditional schooling, we may need to look at new ways of engaging the individual, taking into account “plasticity of development” as well as cultural, community and social environmental contexts. The report also highlighted that apart from emphasizing behaviours and performance there is a need to realize that individuals can be taught metacognitive processes and self-regulatory thinking.
From the pedagogical perspective, PBL is based on the constructivist theory of learning (Schmidt, 1993; Savery & Duffy, 1995; Hendry & Murphy, 1995). In PBL approaches:
- understanding is derived from interaction with the problem scenario and the learning environment
- engagement with the problem and the problem inquiry process creates cognitive dissonance that stimulates learning
- knowledge evolves through collaborative processes of social negotiation and evaluation of the viability of one's point of view
The underpinning philosophy of constructivism in PBL is not new. Four decades ago the well-known philosopher of education John Dewey (1963) wrote:
There is, I think, no point in the philosophy of progressive education which is sounder than its emphasis upon the importance of the participation of the learner in the formation of the purposes which direct his activities in the learning process, just as there is no defect in traditional education greater than its failure to secure the active cooperation of pupil in construction of the purposes involved in the studying (p. 63).
Constructivism has been repeatedly emphasized (e.g. Biggs, 1996; Carlson, 1999), yet in teacher training and in our classroom the reality is often one of didactic teaching with little room for dynamic thinking and dialogue.
PBL in the classroom is not only about infusing problems into the class but also about creating opportunities for students to construct knowledge through effective interactions and collaborative inquiry.
Karl Popper (1992), the famous philosopher of science whose ideas also influenced education, once wrote:
I dreamt of one day founding a school in which young people could learn without boredom, and would be stimulated to pose problems and discuss them; a school in which no unwanted answers to unasked questions would have to be listened to; in which one did not study for the sake of passing examinations (p. 40).
Perhaps a PBL school could be an answer to Popper's dream. In PBL, learners are given the opportunity to find knowledge for themselves and to deliberate with others. They then refine and restructure their own knowledge in the light of prior and new knowledge and experiences. Through self-directed learning, peer learning, team teaching and presentation activities, the cognitive processes are thus enriched.
Developments in cognitive science and neuroscience also support the use of problems in learning. Seeing configurations (the whole is more than the sum of its parts), understanding perceptions, cognitive dissonance, problem solving and insightful learning are important aspects of learning in cognitive psychology. For example, as educators, we are familiar with the use of learning objectives. We organize our lectures and lessons sequentially and systematically with clear and specific learning objectives along each stage. Whilst these may be important in teaching basic facts and establishing foundation knowledge, they are not as effective with developing higher-order thinking skills. The development of insightful and creative thinking does not happen this way. On the contrary, when people are immersed in solving a problem over an extended period of time, they often derive insights and “aha” revelations not in ways in which we sequence learning objectives. There are many aspects of learning, and thinking could perhaps be best developed through immersion in a problem scenario. These aspects may include cognitive functions such as the following:
- Configuring (systems and holistic thinking)
- Observing and making use of observations
- Recognizing and making patterns
- Generating fresh arguments and explanations
- Transforming information
- Playing with ideas
This list is not meant to be exhaustive or systematic in any way. It merely serves to point out that there are many aspects of good thinking and learning that we need to address in a more innovative education system. Figure 2.3 shows the shift needed in addressing our pedagogical paradigms.
Figure 2.4 provides a schema of PBL approaches where problems trigger learning by inquiry, which results in learning to deal with more novel and real-world problems.
Jerome Bruner, at one time Director of the Harvard Center for Cognitive Studies, wrote a famous classic entitled The Process of Education. In it Bruner (1960) argued that the knowledgeable person is a problem solver, one who interacts with the environment in testing hypotheses, developing generalizations and engaging in learning to arrive at solutions. According to Bruner, the goal of education is to further the development of problem-solving skills and the process of inquiry and discussion. As Jim Killian, former president of the Massachusetts Institute of Technology put it: “The basic aim of education is not to accumulate knowledge, but rather to learn to think creatively, teach oneself and seek answers to questions as yet unexplored.”
From the cognitive perspective, all problems have three elements (Mayer, 1983; Chi & Glaser, 1985):
- An initial state (problem situation)
- A goal state (problem resolution)
- Process and means to get from initial state to goal state
In many PBL approaches, the student confronts a situation where he or she needs to accomplish an objective, and the means (i.e. the information, process and actions to be taken) is something new or unknown to the student. In many ways, the pedagogy of PBL helps to make “visible” or explicit the thinking and the richness of the cognitive structuring and processes involved.
Figure 2.5 illustrates how PBL problems affect cognition and learning. A problem triggers the context for engagement, curiosity, inquiry and a quest to address real-world issues. What goes on in the mind of the learner (cognition) and the probable changes in behaviour (learning) include those listed in the right-hand box of the figure.
The challenge in diversifying educational methods is designing learning through the effective use of problems. Depending on the
nature of the discipline, the goals of the curriculum, the flexibility of cross-disciplinary integration and the availability of resources (e.g. time, infrastructure, information systems), problems can be used appropriately, strategically and powerfully.
PBL optimizes on goals, needs and the motivation that drives learning. It simulates the kind of problem-solving cognition needed in real-world challenges. The PBL innovation incorporates the use of e-learning accessibility, creative interdisciplinary pursuits and the development of people skills .
Problems can be used to challenge and empower students to capitalize on the accessibility to and the wealth of knowledge today. Furthermore, the knowledge fields of this century will increasingly be characterized by the creative integration of knowledge from diverse disciplines. Biotechnology, the life sciences, telecommunications, material science and supercomputers are examples of corollaries of effective multidisciplinary pursuits. Many of these pursuits originated from intense curiosity and the motivation to solve real-world problems. The use of PBL approaches aims to enhance such knowledge sharing and enterprise.