Technology education constitutes a separate educational sector of the educational system. Generally, by the term Technology Education (TE) we refer to that particular part of the curriculum that is related to the support offered to students in becoming technologically capable, to the identification of the human needs for which technological solutions are required, to the design and manufacture of suitable products, to the evaluation of product quality and potential social and environmental repercussions (De Vries, 1997, 2005; De Vries & Tamir, 1997). Today TE is undergoing an important transformation. The increasing complexity of society has resulted in a shift of interest from the acquisition of manual skills towards the development of mental skills. The curricula of technological studies in developed countries are changing direction and from providing specific knowledge and practicing skills, emphasis is given to the procedures of problem solving, decision making on technological matters and knowledge of the productive processes (DFE, 1993; ITEA, 2000). Technology educators have to bring together scientific, technological and social knowledge (De Vries, 1997).
Information and Communication Technologies (ICT) are considered to be the most powerful tool for the support of the learning process. ICT with their flexibility, adaptability, their capability of being applied at the work place, their good cost-performance ratio, are being used widely in TE as learning tools. From the various technological approaches of ICT, Virtual Reality (VR) is considered to be the most powerful learning tool, because of its unique characteristics that can be summarized as follows (Mikropoulos & Bellou, 2006):
* creation of three dimensional (3D) spatial representations, namely virtual environments
* multisensory channels for user interaction
* immersion of the user in the virtual environments (VEs)
* intuitive interaction through natural manipulations in real time.
The present work proposes the design, development and evaluation of an Educational Virtual Environment (EVE) in TE for the support of the understanding of the milk production processes as a case study, in a technical school of secondary education. The aim of this study is to investigate the contribution of the proposed EVE to the development of the four different types of technological conceptual knowledge, namely knowledge of the physical nature; knowledge of the functional nature; knowledge of the relationship between the physical and the functional nature, and the process knowledge (De Vries, 2005). For the evaluation of knowledge construction after the EVE-supported intervention, the Structure of the Observed Learning Outcomes (SOLO) taxonomy is used (Biggs & Collis, 1982).
Over the last years a number of VR applications have appeared aimed at the support of the educational process in the field of Technology Education. TE includes a vast number of fields of application such as industry, manufacturing, energy, and transportation; therefore the virtual environments concern a wide variety of applications.
Weyrich & Drewes (1999) have developed a desktop VR system for training in the planning and manufacture of model products, without presenting any empirical data. Parkinson & Hudson (2002) report on the training of 14-16 year old students in the manufacture of automobiles using a desktop system, and found some improvement in the generic process of engineering design. Yap et al. (2003) propose an immersive system for training in the development of industrial products. Their results show a reduction in the design time and the design of more precise products. Hashemipour et al. (2009) present a virtual computer integrated manufacturing laboratory for various engineering disciplines. They report on positive students' attitudes and learning outcomes in undergraduate courses. …