Following the American Psychological Association’s Guidelines
ANSWERS TO QUESTIONS
Report the sample you selected and the question that was explored in the study.
This study explores the relation between the hours of study and the exam scores for a group of students. From the study, we can see whether there is a negative or positive relation between these two variables. For this study 30 students information has been collected.
Report the r2 linear correlation coefficient and the linear regression equation produced in the Excel spreadsheet.
r2 linear correlation coefficient is 0,785 and it is quite high to accept that there is a strong correlation between the two variables. That means hours of study and exam scores have a linear correlation. From the graph, we can see this relation easily. The graph shows that the points are spread around a line. Only a few points are truly away from the line.
What would be the value of Pearson’s r (simply the square root of r2)?
The square root of r2 (0,785) is 0,886. Pearson’s r simply explains us the strength of a relation between two variables in a direction. Pearson’s r might get negative or positive sign. Because we have calculated the square root of r2 , we need to check the scattergram of the variables to decide the sign of the Pearson’s r.
Would Pearson’s r be positive or negative? What does this imply about the relationship between the factors in this study?
The Perason’s r is positive in this case. As we see in the table, while the hours of study increases the exam scores also increase. Thus both variables are moving in the same direction.
What is the implication of any correlation found between the variables in the study you picked?
The study shows that there is a positive correlation between the two variables, therefore we can say that the hours of study has a positive influence on the exam scores. The coefficient of the independent variable is 1.5608. That means if one more hour added to the hours of study, the exam score goes up 1.5608.
Does this correlation imply a causal relationship? Explain.
There might exist a causal relationship between variables. If we make a literature review on the success in the education, we can easily see that there might be a positive relation between hours of study and exam scores. However, the length of hours of study might not explain fully the exam scores. Although we feel causality between these two variables in this case, we might need to use more variables and set up a multivariable econometric model.
Are there other variables that you think should have been examined that would have improved this study or help to pinpoint what factors are causal?
