Question

Research question #2.   Is there a relationship between the relationship between the juveniles’ age and the change of the scores from pretest to posttest (the larger the change, the better the outcome)? (13 points)

SPSS Dataset	SPSS Data for HW (500 cases).sav (available in Canvas)
Variable Names in the dataset	age: Age of juveniles
	change: Change of the scores from pretest to posttest

1. What are the dependent variable (DV) and independent variable (IV)? (1 point)

2. State the research hypothesis (non-directional) and the null hypothesis. Make sure you include both DV and IV in the hypotheses from #1 above. (2 points)

3. Based on the research question, what type of statistical analysis should be used? Explain. (2 point)

Answer 1

1. Here the dependent variable (DV) is Change: Change of the scores from pretest to posttest and Independent variable (IV) is Age: Age of juveniles
2. Research hypothesis is to seek the significant relationship between Age of juveniles(IV) and Change of the scores from pretest to posttest (DV)

Null Hypothesis: There is no significant relationship between Age of juveniles(IV) and Change of the scores from pretest to posttest (DV)

Alternative Hypothesis: There is a significant relationship between Age of juveniles(IV) and Change of the scores from pretest to posttest (DV)

3. Here the statistical analysis to be carried by applying simple linear regression analysis.

We establish a linear relationship as

Y = a + bX using principle of least squares

Where, Y is dependent variable (DV) is Change: Change of the scores from pretest to posttest

And X is Independent variable (IV) is Age: Age of juveniles

We test whether b=0 under null hypothesis against b is not =0 under alter native hypothesis using t test at 5% level of significance.

If calculated modulus of t value is less than the critical value of t, we accept null hypothesis and conclude that there is no significant relationship between Age of juveniles(IV) and Change of the scores from pretest to posttest (DV), otherwise, we reject null hypothesis and conclude that there is a significant relationship between Age of juveniles(IV) and Change of the scores from pretest to posttest (DV)