PROBING STELLAR POPULATIONS OUT TO THE DISTANT UNIVERSE: CEFALU 2008, Proceedings of the International Conference. AIP Conference Proceedings, Volume 1111, pp. 39-47 (2009).
The various methods for studying in detail relevant stellar population parameters throught the integrated light are reviewed. The emphasis is given to the analysis based on absorption line-strength indices. The state-of-the-art of the stellar population synthesis models and methodologies is summarized. Finally some of the various uncertainties and limitations, which are lurking these studies are shown and discussed.