The subject of perturbations of an equilibrium system and the direction in which it shifts as it moves towards a new equilibrium position is an important aspect of general and physical chemistry courses. Perturbations involving intensive variables are subject to moderation while perturbations involving extensive variables are not. However cases are Known where moderation fails even for intensive variables. The problem of moderation can become more complicated when there are several reactions. The researches begin by reviewing the common methods used in textbook to deal with predicting the direction of a reaction shift inducted by a peturbation. The merits and demerits of these method are discussed.