This article demonstrates how theoretical substruction with its variou
s levels of abstraction can be used as a guide for theory testing rese
arch. The article describes a method for substructing research hypothe
ses as well as an entire study. Substruction and its benefits, includi
ng assuring the internal consistency of model testing, are discussed a
s applied to a study testing hypotheses derived from proposition two o
f Orem's self-care deficit theory of nursing. This approach to theory
testing is congruent with the coherence theory of truth and promises t
o contribute to the advancement of nursing epistemology.