American Institute of Certified Planners (AICP) Practice Exam

What statistical method describes the relationship between two variables while keeping one variable fixed?

1. Correlation

2. Regression

3. Variance Analysis

4. Multivariate Analysis

The correct answer is: Regression

The method that describes the relationship between two variables while keeping one variable fixed is regression. In regression analysis, one variable is typically treated as the dependent variable (the one we are trying to predict or explain), while the other variable is the independent variable (the one we are manipulating or keeping constant). This allows planners and analysts to observe how changes in the independent variable influence the dependent variable, thus highlighting the strength and nature of that relationship. In contrast, correlation measures the strengths and direction of a linear relationship between two variables without implying causation or controlling any variables. Variance analysis focuses on how much of the variation in a dataset can be attributed to different sources; it does not seek to establish a direct predictive relationship between variables. Multivariate analysis, on the other hand, encompasses techniques that examine multiple variables simultaneously, but it does not specifically emphasize holding one variable fixed while analyzing another. Therefore, the essence of regression lies in its capacity to systematically analyze the impact of one variable on another by controlling for additional factors, making it essential for planning and predictive modeling in various fields, including urban planning and policy development.