The spelling of the term "linear regression" can be explained using the International Phonetic Alphabet (IPA). The first word, "linear," is pronounced /ˈlɪniər/, with stress on the first syllable and a schwa in the second syllable. The second word, "regression," is pronounced /rɪˈɡreʃən/, with stress on the second syllable and a schwa in the third and final syllable. The word "regression" comes from the Latin word "regredi," meaning "to go back," and a linear regression refers to a statistical method for predicting the relationship between two variables.
Linear regression is a statistical modeling technique used to determine the relationship between one dependent variable and one or more independent variables. It aims to find the best-fitting straight line that describes the linear association between these variables in a given dataset. The dependent variable is generally denoted as y, while the independent variable(s) is denoted as x.
In linear regression, the goal is to minimize the distance between the observed data points and the fitted line. The line is represented by a linear equation of the form y = mx + b, where m is the slope of the line (representing the rate of change between the variables) and b is the y-intercept (representing the value of y when x is zero). The technique utilizes the principles of Ordinary Least Squares (OLS) estimation to estimate the values of m and b that provide the best fit.
Linear regression is widely used for various purposes, such as predicting future values of the dependent variable based on the independent variables, understanding the relationship between variables, and identifying trends and patterns in the data. It is frequently employed in disciplines like economics, finance, social sciences, and engineering.
However, it is essential to consider the assumptions of linear regression, such as linearity (the relationship between the variables is assumed to be linear), independence of errors (the residuals are not correlated), normally distributed errors, and homoscedasticity (constant variance of the errors). Violations of these assumptions may affect the accuracy and reliability of the regression results.
The word "linear regression" originates from combining two terms, "linear" and "regression".
The term "linear" comes from the Latin word "linearis", which means "belonging to a line". In mathematics, linear refers to a relationship or function that is straight or follows a straight line.
The term "regression" was introduced by Sir Francis Galton in the late 19th century as a statistical concept. Derived from the Latin "regressus", which means "a stepping back", regression represents the idea of analyzing data by understanding the relationship between variables and predicting future outcomes.
When combined, "linear regression" represents a statistical technique that seeks to find the best-fit straight line or linear function that represents the relationship between two variables.