In chapter 1, business activity tests, conducted by the IRG (Research Institute of Economic Development, Warsaw School of Economics) since 1986, have been described. Variables observed in individual projects have been presented with concentration on questionnaires used to analyze business activity in manufacturing and construction industries. Research tools used by the RIED werę compared with requirements of the European Union and EUROSTAT, and conchision has been reached that RIED business activity tests are consistent with harmonization requirements. As a result, it is possible to use data collected by the means of questionnaires for international comparisons. Business activity tests are a specific form of monitoring the current State of Polish economy. Regular observations of behavior of enterprises, repeated in monthly (industry) or quarterly (construction) cycles, allow to conclude what kond of behavior dominates among businesses. Getting acquainted with responses of enterprises is particularly important in the period of system transformation. It allows to analyze the rate of changes in various fields of economic activity and to adjust macroeconomic policy tools to phenomena taking place in the economy. Data collected as the result of business activity survey’s allow to analyze business activity as a business cycle. In particular, they make it possible to determine, with advance in comparison to data collected by traditional methods, the critical points of a cycle which point to changes in direction of economic activity. Thanks to that property, so-called early warning indicators are designed. Growing demand for information on real economy makes data collected as a result of business activity tests a valuable source of additional information. To use it, however, it is necessary to find research methods and tools which allow to predict trends on the basis of qualitative data. This study describes efforts to find these tools.