Intradimensional Validity and Interdimensional Compatibility as they Relate to Multidimensionality
The recent proliferation of classroom observational systems creates a potential problem for educational researchers. For example, “how is a researcher to know if he has chosen an efficient system or systems for use in a particular design?” This paper assumes the position that to realize the greatest payoff when applying observational techniques certain conditions pertaining to the validity and scope of each system must be considered and met.
A multi-instrument approach, which is defined as the simultaneous use of more than one observational system, may best be served by utilizing only systems having “content,” “differential,” and “intradimensional (construct)” validity. In contrast, a multi-dimensional approach to be effective, must not only be concerned with the validity of the multidimensional system or unidimensional systems employed, but also with “interdimensionaI” compatibility. Unless these conditions are met, there may be serious questions regarding the degree of confidence that can be placed in the yielded data as well as the subsequent findings in studies using observational techniques.