emma爱地球 · 2025年04月14日
NO.PZ2018101001000037
问题如下：
Which of the following descriptions about multiple R-squared is most likely correct?
选项：
A.
R² is a reliable measure of the explanatory power of the multiple regression model.
B.
R² almost always increases as variables are added to the model.
C.
R² is always smaller than the adjusted R² .
解释：
B is correct.
考点: R-squared and adjusted R-squared.
解析: 对于多元回归来说，R²不是一个具有很强解释力度的可依赖的指标，所以A选项错误。R² 通常大于等于adjusted R²，所以C错误。B选项的描述是正确的，当自变量增加时，R²也会随着增加。
正确的说法是不是r平方大于等于调整后的r平方？
NO.PZ2018101001000037 问题如下 Whiof the following scriptions about multiple R-squareis most likely correct? A.R² is a reliable measure of the explanatory power of the multiple regression mol. B.R² almost always increases variables are aeto the mol. C.R² is always smaller ththe austeR² . B is correct.考点: R-squareanausteR-square解析: 对于多元回归来说，R²不是一个具有很强力度的可依赖的指标，所以A错误。R² 通常大于等于austeR²，所以C错误。B的描述是正确的，当自变量增加时，R²也会随着增加。 本题解析里说“对于多元回归来说，R²不是一个具有很强力度的可依赖的指标”，但不是说R²的值说明模型可以多大比例Y的变动吗，比如R²是90%，说明模型可以Y的90%的变动，那为什么又说R²不是一个具有很强力度的可依赖的指标呢？
NO.PZ2018101001000037 问题如下 Whiof the following scriptions about multiple R-squareis most likely correct? A.R² is a reliable measure of the explanatory power of the multiple regression mol. B.R² almost always increases variables are aeto the mol. C.R² is always smaller ththe austeR² . B is correct.考点: R-squareanausteR-square解析: 对于多元回归来说，R²不是一个具有很强力度的可依赖的指标，所以A错误。R² 通常大于等于austeR²，所以C错误。B的描述是正确的，当自变量增加时，R²也会随着增加。 另外，C为啥不对呢
请问A为什么不对？
R²是不是又称multiple r²？
