Böhmer, RolandSillescu, H.Diezemann, G.Hinze, G.2008-06-122008-06-122002-05-30Sillescu, H.; Böhmer, R.; Diezemann, G.; Hinze, G.: Heterogeneity at the glass transition : What do we know?. In: Journal of Non-Crystalline Solids Jg. 307-310(2002), S. 16-23, doi: 10.1016/S0022-3093(02)01435-7.http://hdl.handle.net/2003/2551510.17877/DE290R-8079We critically discuss the information that can be obtained from experiments with respect to the existence, the life time, and the length scale of dynamical heterogeneity in glass-forming liquids. The ability to select a dynamically distinguishable subensemble and observe its return to the full equilibrium ensemble is illustrated by examples from multi-dimensional NMR. We also discuss non-resonant hole burning spectroscopy as an example for which two separate time scales are involved.enElsevier53010.1016/S0022-3093(02)01435-7article (journal)