Correlation and Coefficient of Determination

Correlation and coefficient of determination are vital statistical tools used to measure the relationship between two variables. Correlation quantifies the strength and direction of this relationship, indicating how closely the variables move together. Meanwhile, the coefficient of determination, often denoted as \( R^2 \), explains the proportion of the variance in one variable that is predictable from the other variable. These metrics are fundamental in various fields, from finance to scientific research, providing insights into the dependencies and predictive power between different sets of data.

Questions
  • What is the difference between r and r-squared?
  • What is the relationship between R-Squared and the correlation coefficient of a model?
  • What is the difference between the R-Squared and adjusted R-Squared when running a regression analysis?
  • How can adjusted r squared be negative?
  • What are the bounds of an R-Squared value?
  • What is the adjusted R-Squared?
  • How does r squared related to standard deviation?
  • How should a scatter plot of data look if there is a positive correlation?
  • What are the limitations to using R-Squared as a measure of the validity of a model?
  • Can an R-Squared value be greater than 1?
  • Why doesn't an R-Squared value indicate anything about causation?
  • Is a model with a high R-Squared value always better than one with a low R-Squared value?
  • Does a correlation between two random variables necessarily imply a direct relationship?
  • Does a correlation between two random variables necessarily imply a causal relationship?
  • How should a scatter plot of data look if there is a negative correlation?
  • What does a negative correlation coefficient mean about a scatter plot of the data?
  • How do you calculate r squared by hand?
  • What is the difference between correlation and association?
  • What does a correlation coefficient indicate about data?
  • What is the relationship between the slope of the least squares regression line and the correlation coefficient?