With the evolution of e-commerce and Online Social Networks, the web information has constantly increased, so the relevance to create methods for automatic knowledge extraction and data mining earned notoriety. Information as opinion evaluation is a point studied by Sentiment Analysis area, which is becoming important nowadays. Be aware of the best reviews is a factor that must be taken into account. Sousa et al. proposed an approach to estimate the degree of importance of reviews about product and services using Fuzzy System, reporting good results. This work proposes an experimental study between their approach using Fuzzy Systems and an execution using Artificial Neural Network to verify which is the most appropriate to solve the problem to estimate the importance of reviews.