A system for the computer-aided measurement of quality and/or process data during the production and/or conversion of a material web, in particular paper or board web, by way of correlation with raw measured data. The raw measured data is present in the form of other quality and process data during the production or conversion process. Measurements of quality parameters in the laboratory may also be incorporated in the raw measured data. The raw measured data is combined to form data sets which in each case are determined simultaneously. Specific laboratory or quality measurements are selected as target data which, by way of at least one soft-sensor algorithm running in a computer-based operation and linking unit, can be calculated from the other data serving as input data, and each data set containing measured data, which relates approximately to the same monitored volume of web and raw material, in particular paper and paper raw material.