Vanderbilt University Medical Center / SCU cluster analysis (Bruehl, Little, Powell) of 216 high-quality UAP reports 1947-2016, screened from 100,000+ raw reports. Statistical quality: silhouette = 0.6 (good). Seven clusters: (1) Disc/sphere — hovers, domes, odd movement (wobbling/falling leaf), daytime or night. (2) Disc/sphere — NO hover, 56.8% pilot sightings, highest radar detection rate, most multiple-UAP events. (3) Cylinder/cigar — LARGEST of all types, most likely to respond to observer actions (“cat and mouse”), median 1,500ft altitude, mostly night. (4) Triangle/delta/boomerang — ALL hover, 92% at night, 32% black, MOST LIKELY to exceed Mach 1 and instantaneous acceleration, distinct lights in 66%+ of cases. (5) Triangle/ovoid — slow-moving, no unusual acceleration, rarely approaches observer. (6) EM EFFECTS EXCLUSIVE — disc/sphere/ovoid, 97% seen within 2,000 feet, most likely to engage with observer, metallic appearance, animal reactions. (7) SOUND-associated — all shapes, closest to observer, near ground level, no acceleration above 10g. Shape was strongest cluster determinant. Random data produced no valid clusters — ruling out statistical noise.