Cooperative Learning and Object-Orientated Development Methods

ion involves taking an entity and focussing on the essential aspects of that entity while ignoring or hiding the non-essential elements. This allows the simplification of complex phenomena. Abstraction is implemented in Object-Orientation via classes and objects. The principle of separation refers to separating the class or object’s observable behaviour from the methods that it uses to achieve this behaviour. Abstraction in ObjectOrientation includes separating the interface to the rest of the “world” (public part of the class or object) from the private data and code thus protecting the private code and data. This reduces complexity. Within an object or class, the data can only be manipulated by its methods. This is called encapsulation. Composition is the third principle of object orientation according to Kafura (2000). It involves building a complex whole system by assembling the parts into a coherent unit. There are two forms of composition in Object-Orientation, namely association and aggregation. Association involves interacting parts that are externaly visible and can be shared among compositions, whereas in aggregation only the whole is visible and accessible with the components being inside the whole. The last principle of Object-Oriented development is generalisation. Generalisation involves the identification and possible organization of common properties of abstraction. This is implemented by inheritance and polymorphism among other methods. The Synergy Between the Principles of Cooperative Learning and ObjectOrientation The first principle of cooperative learning is individual accountability. In Object-Orientation each object can be thought of as individually accountable for the methods and data that are private to it. This is the aspect that enables software reuse. Individual accountability of the separate objects is also evident in the separation principle of Object-Orientation, where objects have both private and public parts. The objects need to interact with other objects or classes as team members need to do in a cooperative learning environment. There is thus interaction through the defined interfaces. These interactions can be via aggregation or association. Interaction within cooperative learning groups can be within the group itself, within subgroups or between group members or subgroups. This face-to-face interaction is the second principle of cooperative learning. Positive interdependence is involved in both the composition and generalisation principles of ObjectOrientation. When one object interacts within another it is dependent on the other object to give valid results. This is especially true if the object inherits the properties of another object. As the components are put together to form a system, each component is positively interdependent on the other components. The social skills aspects and group processing principles are not evident in Object-Orientation itself, but are evident in Object-Orientated development. It is essential for developers of Object-Orientated systems to be able to work in a team, develop good interpersonal skills and resolve conflicts. As each object is independent and yet needs to interact with other objects this is especially important throughout the project life cycle. Planning the system involves defining objects and their relationships to one another. When putting the system together there must be a lot of cooperation and evaluation to make sure that all the parts work well together. Examples of Using Cooperative Learning Methods for Learning Object-Orientated Development Because Object-Orientated development involves writing components that can stand alone and then combining those components into a system, it is easy to create cooperative learning projects that adhere to the principles described above. In order to avoid using the terms component / object / class or class library, the term component has been used in the discussion that follows. The general cooperative-learning techniques are in standard text form with the Object-Orientated /component-based applications of those in italics. The first example of cooperative learning methods is the Jigsaw method (Johnson, Johnson and Smith 1991), where the teacher is involved in putting students into situations where they must depend on one another. This would be suitable for a lower-level class. • The teams are heterogeneous with regard to ability level, sex and race. Students are given training in team building and communications as well as group leadership. This would need to be done for Object-