The demand for good instructional environments presupposes valid and reliable analytical instruments for educational research. This paper introduces the "SMD Technology" (Surface, Matching, Deep Structure), which measures relational, structural, and semantic levels of graphical representations and concept maps. The reliability and validity of the computer-based and automated "SMD Technology" was tested in three experimental studies with 106 participants. The findings indicate a high reliability and validity. The discussion focuses on the development and realization of the three levels of the "SMD Technology" and applications for research, learning and instruction.