Through a study of comparative law and the jurisprudence of the Colombian Constitutional Court1 this book analyzes the different kinds of decisions in the Judicial Review Process and their effects. Professor Martínez classifies constitutional decisions as Interpretative or Conditional, Integrative, and Substitutive. The first ones are those in which the normative efficiency is maintained, but the normative scope is interpreted. The second ones fill a legislative omission, and the last ones expel a regulation and fill the corresponding legal vacuum. Likewise the study analyzes how the court sets the temporal effects of its decisions.