Why do some Cataclysmic Variables Turn Off? (Abstract)

(Abstract only) VY Scl Stars are a class of CVs which fade by as much as five magnitudes at irregular intervals. Dedicated long-term monitoring programs are needed to study such phenomena. We discuss VY Scl stars and other kinds of long-term CV variability, with an emphasis on collaborations with Arne Henden in these studies. We also discuss Arne's work with early low-light-level detectors, experience that has contributed to his broad knowledge of photometric techniques that has been so valuable to the AAVSO. We then show observational evidence that starspots on the secondary star are responsible for CV low states.