2.8 Jean Piaget's Developmental Theory

Cognitive theory has been influenced perhaps no more than by the Swiss psychologist , Jean Piaget. Although Piaget's work began in the early part of the Twentieth Century, it had little influence in the US until the 1960s. Piaget's chief collaborator, Barbel Inhelder, attended the 1959 Woods Hole Conference chaired by Jerome Bruner. This conference precipitated interest in Piaget's ideas on cognitive development and led to a great deal of attention by educators (science educators, especially) and psychologists (Bell-Gredler, 1986).

Piaget's theory focuses on the development of thinking patterns from birth to adulthood. To Piaget learning is an active process, and is related to the individuals interaction with the environment. According to Piaget, intellectual development is similar to the development of biological structures, such as those shown in mollusks. Margaret Bell-Gredler describes Piaget's thinking this way.

"He found that certain mollusks, transported from their calm-water habitat to turbulent wind-driven waters, developed shortened shells. This construction by the organism was essential for the mollusks to maintain a foothold on the rocks and thereby survive in rough water. Furthermore, these biological changes, which were constructed by the organism in response to an environmental change, were inherited by some descendents of the mollusks. The organism, in response to altered environmental conditions, constructs the specific biological structures that it needs." (Bell-Gredler, 1986, p. 193-194)

To Piaget, this biological development describes the nature of intellectual development. Intelligence is the human form of adaptation to the environment. Piaget, and other cognitive scientists, theorize that cognitive structures (mental structures) grow and develop through a process of interaction with the environment. How do these mental structures develop?

Development of Mental Structures

According to Anton Lawson and John Renner (Lawson and Renner, 1986), both science educators, the most important idea in Piagetian theory is that mental structures (which they nicely describe as mental blueprints) are derived from the dynamic interaction of the organism and the environment by means of a process called self-regulation or equilibration. Lawson and Renner also point out that the mental structure comes not from the organism or the environment alone, but from the organism's own actions within the environment. This idea that the individual constructs the mental structure is an underlying principle in all cognitive theories that will be discussed in this chapter.

Let's look at an example of self-regulation in the classroom.of a teacher who applies Piaget's theory. The teacher is presenting a unit on air pressure to the a group junior high students. A demonstration in progress. The teacher heats up a metal can containing a small amount of water. After a few minutes steam begins to rise out of the can. The teacher removes the can from the heat source (a hot plate) and caps it. Then the teacher waits. In a few moments the can begins to cave in, bends to the side and falls over. The teacher then asks students to describe and explain what they observed. For many of the students this event is a contradiction or a discrepancy. Discrepancies produce a state of disequilibrium in which you are literally thrown off balance.

According to Lawson and Renner, the students present mental structures are inadequate to explain the "crushed can" and they must be altered. By means of interaction with the environment (doing experiments and activities on the effects of pressure changes on material objects, for instance), the student can assimilate the new situation, and build new structures. Later in this chapter, in the section that deals with conceptual change teaching, you will find out that it is not an easy matter to change students current mental structures or conceptions.

According to cognitive scientists, there are three additional factors that influence the development of mental structures: experiences with the environment, maturation and the social environment.

Experience with the environment is essential since the interaction with the environment is how new structures are made. Piaget distinguishes between two types of experiences, namely concrete and abstract (logico-mathematical). It is important to remind ourselves that knowledge is constructed through experience, but the type of knowledge will be dependent on the type of experiences the individual is engaged in. Concrete experiences are physical experiences in which the student has a direct encounter with physical objects. Piaget suggested that interaction with material objects was essential to the development of thinking. Lawson and Renner suggest that science teachers should use the laboratory to precede the introduction of abstract ideas (Lawson and Renner, 1986).

Students need more than experiences with the environment, they also need to interact socially. Here the role of language, and verbal interaction in the classroom environment will accelerate or retard cognitive development. The crucial aspect of this factor is that students be given the opportunity to examine and discuss their present beliefs and conceptions. The science teacher should not only provide concrete and abstract experiences with the environment, but must provide for social interaction via the use of language. Small and large group discussions are crucial to the development of cognitive structures.

The third factor facilitating the process of self-regulation is maturation. Piagetian theory is developmental, thereby placing importance on the maturation level of the student.

Cognitive development is a cyclic process involving interaction with new events, materials, properties, and abstractions. Science educators have developed a unique model of learning that is based on Piaget's theory of development.

Cognitive Processes and the Learning Cycle

According to Piaget, the development of new cognitive structures will be the result of three different mental processes: assimilation, accommodation, and equilibration. Cognitive development is the result of the individual's interaction with the environment. The nature of the interaction is an adaptation involving these three mental processes.

Assimilation. Assimilation is the integration of new information with existing internal mental structures. A student who identifies the rock sample as coarse-grained rock as granite is assimilating that rock into his or her schema of rocks. Piaget suggested that assimilation was dependent on the existence of an internal structure so that the new information integrated.

Accommodation. Accommodation is the adjustment of internal structures to the particular characteristics of specific situations, events, or properties of new objects. Biological structures, for example, accommodate to the type and quantity of food at the same time that the food is being assimilated. Piaget theorized that in cognitive functioning, internal mental structures adjust to the unique properties of new objects and events.

Equilibration. Equilibration, like assimilation and accommodation, has a biological parallel. The organism, in biological functioning, must maintain a steady state within itself at the same time remaining open to the environment to deal with new events and for survival. In cognitive functioning, equilibration is the process that allows the individual to grow and develop mentally, but maintains stability. Piaget suggests, however, that equilibration is not an immobile state, but rather a dynamic process that continuously regulates behavior.

This cycle of assimilation, accommodation and equilibration has been used as a basis for the development of several science teaching cycles called the learning cycle. One of these cycles is shown in Figure 2.22 Three teaching processes, exploration, invention and discovery (expansion of the idea) are parallel processes to assimilation, accommodation and equilibration.

Figure 2.22 The learning cycle integrates the three phases of learning: exploration, conceptual invention and discovery (Based on Charles R. Barman, An Expanded View of the Learning Cycle: New Ideas About an Effective Strategy. Monograph and Occasional Paper Series #4, Council for Elementary Science International.

Exploration is an active process involving the students directly with objects and materials. The exploration phase can be open ended, or can be structured by the teacher. The important element is the active engagement of the student for the sake of creating some disequilibrium. During the exploration phase students observe, gather data, and experience new phenomena.

Invention (concept introduction) is the phase in the learning cycle that is analogous to accommodation when new structures are built to integrate new information. Renner calls this phase conceptual invention. The invention process has a high degree of teacher direction. Using the language and experiences of the exploration phase students invent new concepts with the aid of the teacher. The experiences students had during the exploration phase are used as data for a new structure that is proposed by the teacher. The invention phase is interpretive. Students process new information, and modify current conceptions and frameworks in order to accommodate the new information.

The discovery phase is designed to provide the students with active learning situations where they can apply, test and extend the new ideas and concepts. The discovery phase is analogous to equilibration, but like equilibration, it is dynamic. Students, even at this phase, are still in a state of disequilibrium, and require further exposure to active learning lessons. The discovery phase allows the student to apply the new ideas to different situations, further reinforcing the development of new mental frameworks.

This is a brief introduction to the learning cycle. You will find more information on the learning cycle idea and application to science teaching strategies in Chapter 7 and in the section on lesson planning in Chapter 9.

Piaget's Stages of How Students Think

Piaget identified four stages or patterns of reasoning that characterized human cognitive development. Piaget viewed these as qualitative differences in the way humans think from birth to adulthood. At each stage the individual is able to perform operations on the environment in order to develop cognitive structures. A summary of the four stages are shown in Figure 2.23

Sensorimotor stage. Beginning at birth to about 2 years, the first stage is characterized by perceptual and motor activities. The behavior of children during this stage can be described as nonverbal, reflex actions, play, imitating others, and object permanence. Early in this stage of development, if an object which the child has seen is removed from view, the object is forgotten (Out of sight, out of mind). However, later in this stage, if a child was playing with an object, and it gets hidden from view, the child will look for the object.

The child from the beginning is an agent of his or her own cognitive development. Piaget described the young infant as taking control in procuring and organizing all experiences of the outside world. Young children follows with their eyes, explore things, and turn their heads. They explore with their hands by gripping, letting go, pulling, pushing. We all recognize the exploration of children with their mouths. The child continues its exploration with body movements, and extends this exploration by putting hands, eyes and mouth into action at once. With these early life explorations, the child, according to Piaget develops mental schemes or patterns based on these experiences. These experiences, particularly if they are satisfying, will be repeated by the child. Through the processes of assimilation and accommodation, the child builds internal structures; the child adapts to the world.

Near the latter phase of this stage the child's experiences are enriched by means of imaginative play, combined with greatly enhanced exploratory abilities, namely questioning, listening and talking. These activities lead the child to the next stage of cognitive development, the preoperational stage.

Preoperational stage. During the preoperational stage (ages 2 to 7 years), the child's intellectual abilities expand greatly. The child, during this stage, is able to go beyond direct experience with objects. The preoperational child is able to represent objects in their absence, thereby developing the ability to manipulate in the mind. Thus the child can engage in activities such as symbolic play, drawing, mental imagery and language.

The chart below (Figure 2.24) compares how the child's mental abilities change from the beginning of the operational stage to the end of this stage. Note the differences in abilities at the beginning phase during which the child can classify only on the basis of one characteristic, as well as not being able to conserve compared to the latter phase of this stage in which the child can conserve mass, weight and volume.

Concrete operational stage. The concrete operational stage begins around the age of seven, and extends to the ages of 12 - 14. During this stage of development individuals learn to order, classify, perform number operations such as adding, subtracting, multiplying and dividing. They also learn to conserve, develop the ability to determine the cause of events, and space/time relationships.

Concrete operations means that the child is able to perform various logical operations but only with concrete things. An operation is an action---a manipulation of objects . We might think of an operation as a reasoning pattern. Since most of the students that you will teach will be either at the concrete or formal stage of development (or in transition between these stages), we will explore these reasoning patterns in some detail. At the concrete stage there are several reasoning patterns that impinge on science teaching, and ones that will effect students performance in your classroom. These reasoning patterns include: class inclusion, serial ordering, reversibility and conservation (Figure 2.25)

Class inclusion is an important pattern of reasoning in science courses. Class inclusion is a prerequisite for the development of concrete concepts such as animal, plant, rock, mineral, planet. For example, suppose you show a student a picture of some plants (carrot, grass, oak tree, cabbage, dandelion). In this task the student is asked to identify which of the pictures is a plant. Most children will readily include the grass in the category of plant, but not tree, carrot or dandelion. (the tree was a plant when it was little, but now it is big, and therefore a tree). As students grow older and their cognitive development gets more sophisticated, and their experiences widen, they will develop the ability to include all these objects in the general class of plant.

Students are conservers in the concrete stage. For example, they are able to understand that the quantity of a substance remains the same if nothing is added or taken away. To understand this show a student a ball of clay the size of a tennis ball. After the student has observed the ball, roll it into a cylinder. Then ask the student if the cylinder (you can call it a snake or a dog) has more, less, or the same amount of clay as the ball. The student that can conserve mass will respond that the cylinder has the same amount of clay. Conservation abilities develop in different areas such as number, mass, weight, and volume.

The reasoning patterns in the concrete operational stage can be explored by administering tasks to individual students. By administering Piagetian tasks, you can develop insights into the reasoning abilities of your students. You might want to do Activity 2.3, Piagetian Concrete Reasoning Tasks. To compare students' concrete and formal reasoning patterns, you might do Activity 2.4 , The Mealworm and Mr. Short Puzzles.

Formal operational stage. The formal operational stage (over age 14), is in Piaget's theory, the stage where students can think scientifically. They are capable of mental operations such as drawing conclusions, construct tests to evaluate hypotheses, in short an expanded set of logical operations. The logical or formal operations, which again, we will call reasoning patterns include theoretical reasoning, combinatorial reasoning, functionality and proportional reasoning, control of variables, and probabilistic reasoning. According to Piagetian theory most students in high school should be able to exhibit these reasoning patterns. However, research studies have shown that many students have not developed these reasoning abilities. These may, in fact, be aspirations and goals of science education, rather than descriptions of student's cognitive functions.

The scientific reasoning patterns at the formal operations level are shown in Figure 2.26. At this stage of development students are capable of organizing information and analyzing problems in ways that are impossible for a student at the concrete operations stage.