The variables used in statistical research can be measured on different scales. According to Stevens the most common division of measurement scales distinguish four main types: nominal, ordinal, interval and ratio. The chosen scale of measurement implies further the possibility of applying certain statistical methods. For socio-economic research it is frequent that among independent variables appear variables of a qualitative nature. This study presents the idea of the application of the Likert and Osgood scales for the evaluation and quantification of qualitative variables in the real estate valuation process.