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DATA ANALYSIS - PRACTICAL. Analysis of Variance (ANOVA) using SPSS 14 Computer programme Prof Dr. Md. Ruhul Amin. Problem No. 1.
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DATA ANALYSIS - PRACTICAL Analysis of Variance (ANOVA) using SPSS 14 Computer programme Prof Dr. Md. RuhulAmin
Problem No. 1 Litter weight(kg) in first kidding in three different breeds of goats were as follows. Performing ANOVA, test whether any difference exists among the breeds. Compare each pair of means.
ANOVA…. • Go to SPSS 14 spread sheet • Click on the Variable view at the bottom 3. Define each of your variables i)Breed: label =3 ii) Breed: 1=jam, 2=kam, 3=sir (values) iii) Litter wt. iv) For typing data go to Data view sheet
Analysis… • Go to “Analyze” button • Select “compare means” • Select “One-way ANOVA” • Bring lwt as dependent variable • Select “Post hoc” • Click “OK”
ANOVA Value of F is significant (p<0.001) There is significant difference (p<0.001) between litter wt. of goats in 3 different breeds.
Post hoc Test (Duncan’s test) Lwt Duncan a,b Kam 1.97c Sir 2.70b Jam 4.13a
Interpretation of post hoc test Significantly (p<0.05) highest lwt. was observed in Jamnapari, lowest was in KambingKatjang and the Sirohi ranked intermediate.
Interaction effect Suppose records on litter weight of goats shown in Problem 1 were obtained randomly from 3 flock located on 3 states of Malaysia. Obviously “FLOCK” may have an effect like “BREED”. Again different combination of BREEDxFLOCK may behave differently. This is called interaction effect. Total no. of interaction will be 3x3 = 9.
Two-way ANOVA F value for interaction effect