This paper outlines the methodology for calculating a high-frequency indicator of economic activity in Russia. News articles taken from Internet resources are used as data sources. The news articles are analysed using text mining and machine learning methods, which, although developed relatively recently, have quickly found wide application in scientific research, including economic studies. This is because news is not only a key source of information but a way to gauge the sentiment of journalists and survey respondents about the current situation and convert it into quantitative data.