This thesis presents an interpretation of Vygotsky's 'Zone of Proximal Development' (ZPD) which builds upon the increasing acceptance of computers into the culture of the school classroom and respects the need for educational software to be integrated with the broader teaching strategy of the school. The computer is cast in the role of a more able partner for the learner. The notion of the ZPD is extended and clarified to encompass two further concepts. The Zone of Available Assistance (ZAA) and the Zone of Proximal Adjustment (ZPA). The first of these concepts describes the various forms of assistance that are at the disposal of the more able partner. The second concept: the ZPA, defines the quantity and quality of assistance that is selected for use in particular collaborative activities of learner and partner. The interpretation of the ZPD is used in the formulation of a software design framework. This framework is implemented in the 'Ecolab' software which offers instruction about food webs to primary school children. There are three system variations within the 'Ecolab', each of which has a different instructional profile: VIS is based upon the Vygotskian instructional model used in the construction of the design framework. WIS is inspired by a contingent approach to instruction and NIS is a system which makes no instructional decisions for the child. The development of WIS and NIS has allowed the effective evaluation of VIS. An empirical evaluation study, undertaken with a class of 10-11 year old children, confirmed the viability of the partnership role allocated to the computer system. It also supported the hypothesis that interactions which are consistent with the creation of a ZPD between system and child generate increased learning gains. The interactions which occurred when the system attempted to adjust the demands of the learning encounter to a particular user, were also more sensitive to variations in learner ability and learning style. The implementation of the 'Ecolab' shows that a concept like the ZPD can be interpreted in a manner which is informative to the software design process.
This paper is not available online