Not necessarily. If the measurement data conforms to the normal distribution, the mean standard deviation is adopted; If it does not conform to the normal distribution, it is described by median and quartile interval. Dissertation is a research report or scientific paper written by the author to obtain a certain degree. It is generally divided into three levels: bachelor's thesis, master's thesis and doctoral thesis. Among them, the doctoral thesis is of the highest quality, which is an original scientific research work and the focus of collection and utilization.