Hadrons in Medium - Observables

The observable consequences of a lowering of the restmasses of vector mesons on dilepton spectra in the SIS energy regime (HADES) and on photoabsorption cross sections on nuclei are studied in a transporttheoretical framework. We also investigate the consequences of a mass-shift of kaons in dense matter and compare with recent SIS data. The need for a detailed understanding of the elementary processes is underlined.