We have performed photometric optical observations of a sample of 16 radio loud and 16 radio quiet quasars. The aims were to confirm the existence of microvariations in strictly radio quiet objects, and to compare the properties of the variations in both types of quasars. The samples were defined in such a way, that the only observational difference between the two groups is the radio power. We present a new observational and statistical procedure for searching for microvariability, based on the Annalysis of Variance. We have found that microvariations in radio quiet objects may be as frequent as in radio loud sources.