Progress in characterization of electronic materials over the past 50 years will be illustrated by selected examples of determination of the atomistic reconstruction and formation of electronic states at surfaces and interfaces of semiconductors using surface sensitive characterization techniques. The same techniques have been used to characterize reactions at interfaces and determine the mechanisms by which charge carrier transport is changed from that controlled by Schottky rectifying to contacts with ohmic characteristics. Seconday ion mass spectrometry (SIMS) has been used to measure dopant profiles over dimensions <10 nm below the surface, and optical characterization techniques have been used for real time control of semiconductor growth. Finally, areas of future development in electronic materials characterization techniques will be the subject of speculation.