Bivariate Data Analysis: Regression and Correlation.

Bivariate Data Analysis: Regression and Correlation.

1. This analysis allows to see the ralation between two or more characteristics, with the purpose of find relations between them. The characteristic's nature (nominal, ordinal or numeric) will determine the correct tools for the analysis.

   • Bivariate measures
     • - Regression.
     • - Correlation.
     • - Simple linear regression.
     • - Determination coefficient R².
     • - Dispersion diagram.

2. REGRESSION

   • It consists in estimate the relation between quantitative variables, applying formulation of differential equations.
     • Multiple regression → Two or more variables
     • Logistic Regression → Categorical variable (Limited number of categories)
     • Simple linear regression → One variable.
   • Frequent troubles
     • No homogeneous variance
     • No lineal relation
     • Correlation mistakes

3. CORRELATION

   • Measure the proximity that relates two variables on a scale interval. The connections exist when the values ​​of a variable varies constantly respectly to the other.