The authors report measurements of the effects of high-energy ( approximately 60 MeV) H and He ion irradiation of thin films of YBa/sub 2/Cu/sub 3/O/sub 7- delta / produced by plasma-arc spray and laser evaporation, and of low-energy ( approximately 10 MeV) B and N ion irradiation of laser evaporated films. The observed changes in the resistance versus temperature behavior for H and He ion irradiation of the plasma-arc spray films are much more dramatic than that observed for films produced by other techniques and resembles, qualitatively, a bond percolation threshold. In contrast, high-energy H and He ion irradiation of the laser-evaporated films resulted in a negligible change in the resistance-temperature behavior. Low-energy B and N ion irradiation of laser-evaporated films gradually lowered the completion temperature of the superconducting transition. >