COR AND REG ANALYSIS

• Gregor Mendel


  • Known for his experiment using seven groups of sweet pea seeds
  • Invented the scatter plot to graph the data
• Degree of relationship


  The measure of correlation between the variables under consideration
• Correlation coefficient


  • The degree of relationship expressed by a coefficient which ranges from -1 ≤ r ≥ +1
  • The direction of change is indicated by a sign
• Purpose of correlation analysis

  1. To discover whether there is a relationship between variables

  2. To find out the direction of the relationship whether it is positive, negative or zero

  3. To find the strength of the relationship between the two variables
• Kendall Rank Correlation

  A non-parametric test that measures the strength of dependence between two variables
• Spearman Rank Correlation

  A non-parametric test used to measure the degree of association between two variables
• Pearson r Correlation

  Widely used in statistics to measure the degree of relationship between linear related variables
• Pearson Product Correlation Coefficient


  Denoted by r, measures the degree of the relationship
• Pearson Product Correlation Coefficient Calculation 2

  • Given data for number of selfies posted and science test scores
  • Instructed to solve for the Pearson Product Correlation Coefficient
• Regression analysis


  A technique of studying the dependence of one variable (dependent variable), on one or more variables (explanatory variable), with a view to estimating or predicting the average value of the dependent variables in terms of the known or fixed values of the independent variables
• correlation analysis : - The degree of relationship between the variables under consideration