In this chapter, we describe a scientometric assessment tool that was first introduced as early as the second half of the 1980s, but due to the high computational requirements at that time, the method fell undeservedly into oblivion. The method is called Characteristic Scores and Scales (CSS) and is aimed at providing a more detailed picture of citation impact, with particular regard to the high end of performance. More than two decades after its introduction, the method experienced a revival as a consequence of the burning need for improved and versatile assessment tools, facilitated by the rapid development of information technology and the broad access to electronic data sources. The first part of this chapter will describe the model, its background and the statistical properties underlying this approach, while the following sections will deal with its implementation within the framework of research evaluation frameworkof research evaluation at different levels of aggregation and in various disciplinary and multidisciplinary contexts. Special attention is paid to the applicability to various aggregation levels, such as national research performance, the comparative analysis of institutional research output, as a tool to assist the assessment of individual researchers and as journal impact measures. A graphical sketch of possible applications is used as a road map throughout the chapter to navigate the various methodological issues and fields of use. The chapter begins with a review of previous work, but also aims at presenting new insights and applications in a systematic manner. In addition to the presentation of new results, future perspectives and possible applications of this model within and outside traditional scientometrics will be sketched and highlighted.