There is a considerable body of literature on research validity across different disciplines. With regard to rehabilitation research, however, this body is narrow and warrants further consideration. Classification of research validity has been considered and developed over the past six decades; however, a literature search returned no comprehensive discussion that has gathered all available classifications under an overarching umbrella. The aim of this chapter is to provide an all‐inclusive classification of different types of research validity, focusing on rehabilitation research. A basic review of the body of literature available was conducted. Different classifications of validity in the literature were recognized, considered, unified, and are presented in this chapter. Moreover, the main threats to each type of validity and some strategies to minimize them are discussed. A classification of all types of validity in rehabilitation research is presented in this chapter. Furthermore, the matter of priority between these research validities is discussed. It is concluded that while all types of research validities are important to be considered, maximizing all of them in one research project is sometimes controversial. Thus, researchers should make a situation‐based trade‐off between different aspects of validity in order to optimize the overall validity of their research.
Part of the book: Physical Disabilities