The recent discoveries in the neutrino sector in the Standard Model have opened a new frontier in high energy physics. Understanding neutrinos and how they interact is crucial to continuing to verify the Standard Model and look for beyond Standard Model physics. The MiniBooNE experiment is a /spl nu//sub /spl mu///spl rarr//spl nu//sub e/ oscillation search designed to confirm or rule out the neutrino oscillation signal seen by the LSND experiment at the Los Alamos National Laboratory. The MiniBooNE detector, a sphere filled with mineral oil and lined with 8" Hamamatsu photomultiplier tubes (PMTs), uses Cerenkov imaging to identify /spl nu//sub /spl mu// and /spl nu//sub e/ interactions. The PMTs are the main detector component and must be well understood. They underwent a series of tests to determine their functionality and figures of merit in order to be placed in the detector, as described here.