A Stanford Medicine professor, Emmanuel Mignot, is a leading expert on the relationship between age and sleep. He emphasizes the importance of developing good sleep habits, and proposes a new concept called "SleepAge" which estimates sleep quality by analyzing sound spectrograms. This method is different from existing assessment methods. "Sleep age" is also used to predict mortality risk based on EEG readings. Dan Gartenberg, a Ph.D., has conducted research and developed technology to improve sleep by utilizing sound, light, and temperature factors. Experts have been vetted to provide a solution for determining whether hours of sleep on weeknights are independent of age, and a test of independence can be conducted with a significance level of .05.