英文文献中“variance”和“variation”的不同是什么

Variance and variation are two commonly used terms in statistics, but they are often confused. Variance is a measure of dispersion, while variation is a measure of deviation.Variance is defined as the average squared deviation from the mean, and it is often represented by σ^2 in mathematical notation. Variance measures how spread out a set of data is, and it is used to calculate standard deviation, which represents how far each value is from the mean.On the other hand, variation can be calculated using either standard deviation or interquartile range (IQR). Standard deviation is a measure of dispersion that represents how spread out a set of data is. It measures how far each value is from the mean by calculating the average squared deviation and dividing by n-1.IQR is another measure of variation that represents how far apart values are within a dataset. It is calculated by first sorting data from lowest to highest, then calculating the difference between the first quartile and third quartile.In summary, variance is a mathematical concept used to measure dispersion in statistics, while variation can be calculated using standard deviation or IQR depending on the context and purpose of analysis. It is important to understand these differences when analyzing data in order to draw meaningful conclusions from them.