Modern lightweight floor systems are susceptible to annoying vibrations induced by the forcing action of human locomotion. This investigation considered several experimental methods to reduce unwanted floor motion as well as analytical procedures aimed at a better understanding of the phenomenon. A series of test floors were designed and constructed expressly for vibration experiments. Various viscoelastic treatments and second mass damper devices were applied to each test floor and the resulting reduction of vibration tendency was measured. These results are compared and the best-performing treatments and devices are discussed and investigated in detail. The relationship of frequency ratios of structural components was investigated analytically and reasonable design precautions necessary to avoid beating vibrations are discussed. A mathematical model of the forcing function of human locomotion is presented, as well as its implications for statistically-based design criterion. Finally, recommendations for future research are discussed based on the experimental and analytical results of the investigation. / Master of Science