bivariate statical measures regression and correlation

bivariate statical measures regression and correlation

1. correlation analysis

   • measures the closeness of the relationship between two or more variables

2. is used to

   • correlation
     • statistical technique used to measure the closeness of the linear relationship between two or more variables on an interval scale

3. bivariate statistical measures

   • determination coefficient r2
     • simple linear correlation
       • positive correlation and negative correlation
         • Dispersion diagram
           • regression
             • simple regression
               • multiple regression

4. regression problems

   • non-homogeneous variance
     • non-linear relationship
       • correlation errors

5. lienal regression

   • Pearson's linear correlation coefficient if the points have a tendency to be arranged in alignment
   • r is useful to determine if there is a linear relationship between two variables. but it doesn't work for (quadratic, logarithmic)
   • has the same sign as sxy

6. regression analysis

   • It is used to derive an equation that relates the criterion variable with one or more prediction variables, in which the frequency distribution of the criterion variable is considered when one or more of the prediction variables are kept fixed at various values.

7. is used to

   • regression
     • data analysis technique that predicts the value of unknown data by using another related and known data value. Mathematically models the unknown or dependent variable and the known or independent variable as a linear equation
       • regression problems
         • non-homogeneous variance
           • non-linear relationship
             • correlated errors
       • simple linear regression model
         • statistical; allows the incorporation of a random component in the relationship
           • standardized: the slope b1 tells us if there is a relationship between two variables
             • deterministic: that under ideal conditions the independent variable can be a mathematical function of the independent variables
       • covariance of two random variables x and y
         • between the variables sxy, it tells us if the relationship between two variables is direct and inverse
           • The sign of the covariance tells us that the cloud of points is increasing or not but it says nothing about the degree of the relationship between variables.