Ancova and Mancova

This is the basic explanation on what are ANCOVA and MANCOVA in research study in which provides the definitions and the illustration on how can these both be use in SPSS tool analysis. If you's like to get practice file, do not hesitate to contact me.

1. “ ANCOVA AND MANCOVA ” Presented by: PRUM rotana (Ms.) Date: Feb 17 th , 2019 The University of Cambodia 1 The University of Cambodia College of Education Workshop on “ SPSS Analysis for MRP and Thesis”

2. Content 1. COVARIANCE 2. ANOVA 3. MANCOVA The University of Cambodia 2

3. Covariance the mean value of the product of the deviations of two variates from their respective means. provides insight into how two variables are related to one another . A positive covariance means that the two variables at hand are positively related, and they move in the same direction.  A negative covariance means that the variables are inversely related, or that they move in opposite directions.  3 The University of Cambodia

4. Covariance 4 The University of Cambodia

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6. ANCOVA Analysis of covariance (ANCOVA) is used in examining the differences in the mean values of the dependent variables that are related to the effect of the controlled independent variables while taking into account the influence of the uncontrolled independent variables. 6 The University of Cambodia

7. Example Question of ANCOVA Does test score effect by the level of Education regarding the number of hours spent studying? 7 Independent Variable Moderating Variable The University of Cambodia

8. Why Ancova ? * In experimental designs, to control for factors which cannot be randomized but which can be measured on an interval scale. * In observational designs, to remove the effects of variables which modify the relationship of the categorical independents to the interval dependent. * In regression models, to fit regressions where there are both categorical and interval independents. The University of Cambodia 8

9. Practice Research Question Does Weight Loss is influenced by Diet controlling by Height? DV: Weight Loss IV: Diet Moderator: Height Download: ANCOVA PRACTISE The University of Cambodia 9

10. ANCOVA IN SPSS The University of Cambodia 10 Create WEIGTH LOSS Variable Transform  Calculate Variable

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12. Analyze  General Linear Model Univariate The University of Cambodia 12

13. Click on ‘Option’ botton 13 The University of Cambodia

14. Click ‘Continue’  Ok The University of Cambodia 14

15. Interpretation Among the 3 types of diet, Vegetarian Diet is more effective for Weight Loss. Mean= 3.153 Std. is similar between each type YET there is an idea that : The University of Cambodia 15 Height will add more influence on Weight Loss

16. Tests of Between-Subjects Effects Dependent Variable: Weight loss Source Type III Sum of Squares df Mean Square F Sig. Partial Eta Squared Corrected Model 7.523 a 3 2.508 4.165 .012 .258 Intercept .888 1 .888 1.475 .232 .039 Height .033 1 .033 .054 .817 .002 Diet 7.118 2 3.559 5.912 .006 .247 Error 21.673 36 .602       Total 303.724 40         Corrected Total 29.195 39         a. R Squared = .258 (Adjusted R Squared = .196) Since p= .006, Diet has significant effect on weight loss. Moreover, it has moderate effect on weight loss as Partial Eta Squared is only .247= 24.7%. Note: 0.2  Small effect 0.5 Moderate effect 0.8  Large effect The University of Cambodia 16

17. Since ANOVA is Significance, Post Hoc test are carried out Analyze  Compare Mean One-way Anova The University of Cambodia 17

18. Inserting Height: Vegetarian Diet is still more effective than others with Mean= 3.141 No Height: Vegetarian Diet proceed others with Mean= 3.153 Conclusion: The University of Cambodia 18 The Effect of Height had been removed or not account for weight loss

19. MANCOVA The University of Cambodia 19

20. Research Questions Do the various school assessments vary by grade level after controlling for gender? IV: grade level DV: various school assessments Moderator: gender The University of Cambodia 20

21. Which diseases are better treated, if at all, by either X drug or Y drug after controlling for length of disease and participant age? IV: X drug or Y drug DV: Diseases Moderator: length of disease and participant age The University of Cambodia 21

22. Do the rates of graduation among certain state universities differ by degree type after controlling for tuition costs? IV: Degree type DV: the rates of graduation Moderator: Tuition costs The University of Cambodia 22

23. MANCOVA Multivariate Analysis of Covariance an extension of analysis of covariance methods to cover cases where there is more than one dependent variables and where the control of concomitant continuous independent variables – covariates/Moderator – is required . The University of Cambodia 23

24. MANCOVA The University of Cambodia 24

25. Type of MANCOVA Do gender and the outcome of the final exam influence the standardized test scores of math, reading, and writing ? IV: the outcome DV: test scores (math, reading, and writing) Moderator: : gender The University of Cambodia 25 One-way MANCOVA

26. Two-way MANCOVA 2 IVs + 1 Moderator + 2 or more DVs The University of Cambodia 26

27. One-way MANCOVA IN SPSS Research Question Are the number of working hours and income influenced by the age group within the level of education? Download: MANCOVA File Practice The University of Cambodia 27

28. The University of Cambodia 28 Analyze  General Linear Model Multivariate

29. Data Interpretation The University of Cambodia 29

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32. Thanks for Your Attention…!!! The University of Cambodia 32