statistical measures bivariate regression and correlation

statistical measures bivariate regression and correlation

1. bivariate statistics

   • They allow joint analysis of two characteristics of the individuals of a population for the purpose of detecting possible relationships with each other.
     • Both quantitative variables
       • Dispersion diagram
       • Correlation coefficient Pearson linear
         • The percentage of Y variability explained due to the variability in X lo measures the coefficient of determination that corresponds to r2
           • X: score in a learning system Y: cost associated with achieving the score
       • Inference
         • Ha:variables are not independent (variables related)
         • Ho: The variables are independent (variables not related)
     • Both quantitative variables
       • questionnaire
       • data table
       • condensed code table
         • frequency table or contingency table
           • graphic representation

2. Regression and correlation

   • Graphically the scatterplot or point cloud allows to obtain observation about the type of relationship between X and Y.
     • Correlation
       • Examine the direction and strength of the association between two antitative variables. So we will know the intensity of the relationship between them and if, by increasing the value of a variable, increases or decreases the value of the other variable.
     • Regression
       • Describe the relationship between two variables, X and Y.
         • Through regression techniques we invent a variable Y as a function of another variable X, or vice versa