Abstract: The invention relates to a method for measuring personal satisfaction by means of a device for giving feedback, which comprises an internal power source and at least two selector switches for giving feedback, indicating the type of the feedback, a memory for storing feedback data, and a data transmission module for transmitting the feedback data. The method comprises: presenting the subject for the feedback, receiving feedback from at least one person giving feedback, on the basis of the selection of a selector switch, storing the data on the feedback in the memory of the device for giving feedback, and transmitting the feedback data at a predetermined time from the device for giving feedback to a server in a wireless manner. The invention also relates to a device for giving feedback and a data processing system to be used in the method.