In this paper we distinguish two "dimensions" of the utility concept. The first is the "behavioral" dimension, described by indifference curves in a commodity space. It may be estimated by observing consumer purchase behavior. The second dimension is the "welfare" dimension, i.e., the cardinal utility levels . corresponding to indifference curves. The second dimension may be estimated by means of the income evaluation approach. In this paper we deal with methodological issues and show by means of empirical evidence the validity of the income evaluation approach. In the same time we propose some major modifications of the method. Secondly we show how the two dimensions may be combined. This is illustrated with respect to the AIDS- and the Translog- model. In this way we find how price and income variations influence measured individual welfare.