Quantitative assessment of communication efficiency and users' preference: experiments worth improving

With the expanding possibilities of computer-controlled consumer products and the accordingly increasing complexity of manipulation, ease of use becomes an attribute of growing importance. Since it is a rather vague concept covering a variety of aspects, this paper describes a method which permits quantitative assessment of ease of use and its deciding factors. In particular, the preference subjects show for using specific entry devices as a function of their communication efficiency has been investigated. Users' preference for performing a given data-entry task by means of one of the available input devices could be manipulated by experimental variation of the relative speed and accuracy of the interaction. Our preliminary results show the proposed method to be a promising means of quantitative assessment of the determinants of ease of use. Accordingly, suggestions are given for further improvement of the experiments.