The introduction of hydrophilic functional groups at the surface of poly(4-methylstyrene) provided a system for studying the thermal reconstruction of the surface of a glassy polymer at temperatures below, at, and above the glass transition temperature (T-g). Partial or "frustrated" reconstruction was observed at temperatures below the T-g of the polymer, and complete reconstruction occurred above it. The frustrated reconstruction indicates that although collective motion of segments entangled in the bulk is governed by the T-g, those segments at the surface are rubbery well below this temperature. In fact, analysis of the initial kinetics of reconstruction as a function of temperature revealed no discontinuity in the activation energy for diffusion at or near the T-g.