The Advantages & Disadvantages of a Multiple Regression Model

Level of Familiarity

• Multiple regression is one of the most commonly used statistical techniques, and many people are familiar with it, at least in outline. This will be especially true of people educated in the social, behavioral or physical sciences; for this audience, familiarity is an advantage. On the other hand, if your audience is the general population, then many people will be unfamiliar with multiple regression; for this audience, familiarity is a disadvantage, and you might want to use a simpler statistic or rely entirely on graphs.

Assumptions

• Multiple regression makes four assumptions, and these need to be checked. The assumptions are about the errors from the model; the errors are the difference between the predicted value of the dependent variable and the actual value of the dependent variable. Multiple regression assumes that the errors from the model are normally distributed; that the errors have constant variance; that the mean of the errors is zero; and that the errors are independent.

Flexibility

• Multiple regression is a very flexible method. The independent variables can be numeric or categorical, and interactions between variables can be incorporated; and polynomial terms can also be included. For example, in examining the relationship between weight and height, age and sex, you could include height squared and the product of height and sex.
  Then the relationship between height and weight would be different for men and women, and the predicted difference in weight between a 5-foot-tall person and a 5-foot-1 person is not the same as that between a 6-foot-tall person and a 6-foot-1 person.

Use of Multiple Variables

• Multiple regression uses multiple independent variables, with each controlling for the others. For example, in the model of weight as related to height, age and sex, the model estimates the effect of height controlling for sex. The parameter for height answers the question "What is the relationship between height and weight, given that a person is male or female and of a certain age?"