Educational technology research has moved through several stages or "ages", focusing at the beginning on the content to be learned, then on the format of instructional messages and, finally on the interaction between computers and students. The present paper reviews the research in technology-based learning environments in order to give both a historical perspective on educational technology research and a view of the current state of this discipline. We conclude that: 1) trends in educational technology research were forged by the evolution of learning theories and the technological changes, 2) a clear shift from the design of instruction to the design of learning environments can be noticed; 3) there is a positive effect of educational technology on learning, but the size of the effect varies considerably; 4) learning is much more dependent on the activity of the learner than on the quantity of information and processing opportunities provided by the environment.
KEYWORDS: educational technology, computer- based learning, learning environments, research methods, virtual reality.
Computer technology and the tremendous development of information technologies over the last few years have transformed the way education is conducted nowadays (Lou et al., 2001). Although computer technology has the potential of a powerful and flexible tool (Scardamalia & Bereiter, 1996), the previous experiences with the integration of early technologies in schools (e.g., radio, television, early computer-assisted instruction) underline the fact that the mere installing of hardware does not lead to desired results (Clark, 1983). Thus, the main question, research tried to find an answer for, was and still remains whether computer technology is benefic for the learning process and if yes, in which conditions?
The "proper research of educational technology" has represented the subject of a debate for more than a decade (Lagemann, 2000; Levin & O'Donnell, 1999; Shavelson & Towne, 2002; Slavin, 2002). Despite of the accumulated experience in conducting research and publishing results in specialized journals, there is no consensus regarding methods that are used, or results and interpretations that are given to them (Hannafin, 2006). Reeves (1993) claimed that an important part of the research in the educational technology field is "pseudoscience", because it fails in meeting the high level of theoretical, conceptual, methodological and/or analytical requests of the paradigm that it is based upon.
The purpose of this article is to review the research performed in the educational technology field in order to understand the nature of questions and problems that researchers had to face in this field over the years, and also to place the current research in the context of educational technology research.
THE EVOLUTION OF RESEARCH IN EDUCATIONAL TECHNOLOGY
The field of educational technology found its origins in the discovery made by researchers and practitioners of the fact that the instruction can be planned, projected, evaluated and revised before being applied on students. In other words it can be treated as an object on which a set of procedures, (i.e., technologies) can be applied (Winn, 2002).
Educational technology is, according to the definition of the Association for Educational Communications and Technology (AECT), "...the theory and practice of design, development, utilization, management and evaluation of processes and resources for learning" (Seels & Richey, 1994, p. 231). Another definition is the one offered by Reisser (1987), who states that educational technology is the systematic way of designing, utilization and evaluation of the teaching/learning process, in terms of specific objectives, based on research in human learning and communication fields and on combining human and technical resources.
The research made in the educational technology field, according to Winn (2002) has moved through four stages or "ages", each being built on the previous one and each of them being characterized by a specific focus, specific theoretical assumptions and practical implications. …