statdad said:
Multiple linear regression is a statistical method used to analyze the relationship between two or more independent variables and a single dependent variable. It is commonly used to predict the value of the dependent variable based on the values of the independent variables.
Simple linear regression involves only one independent variable, while multiple linear regression involves two or more independent variables. This allows for a more complex analysis of the relationship between the variables and can provide more accurate predictions.
A QQ plot, or quantile-quantile plot, is used to assess the normality of the residuals in a multiple linear regression model. It compares the quantiles of the observed residuals to the quantiles of a theoretical normal distribution, and any deviations from a straight line can indicate non-normality in the data.
If the points on the QQ plot fall close to the straight line, it indicates that the residuals are normally distributed, which is a desirable outcome. However, if the points deviate significantly from the line, it suggests that the residuals may not be normally distributed and further investigation may be needed.
Yes, QQ plots can be used to assess the normality of residuals in various types of regression models, such as logistic regression or polynomial regression. However, the interpretation may differ slightly depending on the specific model and its assumptions.