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Students often complain that having final exams at scheduled times that are diff

ID: 3292515 • Letter: S

Question

Students often complain that having final exams at scheduled times that are different from regular class sessions disrupts their circadian rhythms and affects their performance. You suspect that this might be so and that the impact would be greatest for more difficult exams. To test this, you conduct a 2 times 3 between-subjects experiment in which difficulty level and time of testing are varied for a sample of students who are taking final exams at "different" times. Using the data presented below, test whether performance depends on time of day and difficulty level of the exam. Perform the appropriate analysis using SPSS. Please write up the results as you would in a scientific paper. For any significant main effects, please report the effect size. Please turn in the relevant portions of your SPSS output.

Explanation / Answer

Solution:

Test Hypothesis:

H0: Test difficulty and Time of testing independent.

H1: Test difficulty and Time of testing not independent

Chi square test will be appropriate for given data. Now using SPSS, we get the result.

Case Processing Summary

Cases

Valid

Missing

Total

N

Percent

N

Percent

N

Percent

Test_Difficulty * Time_Testing

160

100.0%

0

.0%

160

100.0%

Test_Difficulty * Time_Testing Crosstabulation

Time_Testing

Total

9am

12am

3pm

Test_Difficulty

Difficult

Count

11

25

40

76

Expected Count

24.2

26.1

25.7

76.0

Std. Residual

-2.7

-.2

2.8

Easy

Count

40

30

14

84

Expected Count

26.8

28.9

28.4

84.0

Std. Residual

2.6

.2

-2.7

Total

Count

51

55

54

160

Expected Count

51.0

55.0

54.0

160.0

Chi-Square Tests

Value

df

Asymp. Sig. (2-sided)

Pearson Chi-Square

29.136a

2

.000

Likelihood Ratio

30.627

2

.000

Linear-by-Linear Association

28.873

1

.000

N of Valid Cases

160

a. 0 cells (.0%) have expected count less than 5. The minimum expected count is 24.23.

Conclusion: Here Pearson Chi-square value is 29.136 and p-value=0.00.

Since p-value<0.05

Hence, we reject H0 and conclude that "Test difficulty" and "Time of testing independent" are not independent.

Case Processing Summary

Cases

Valid

Missing

Total

N

Percent

N

Percent

N

Percent

Test_Difficulty * Time_Testing

160

100.0%

0

.0%

160

100.0%