Question 9

# a.Assume that both Temperature and Position are fixed effects.
library(GAD)
## Warning: package 'GAD' was built under R version 4.2.2
## Loading required package: matrixStats
## Loading required package: R.methodsS3
## R.methodsS3 v1.8.2 (2022-06-13 22:00:14 UTC) successfully loaded. See ?R.methodsS3 for help.
Position<-c(rep(1,9),rep(2,9))
Temperature<-rep(seq(1,3),6)
observation<-c(570,1063,565,565,1080,510,583,1043,590,528,988,526,547,1026,538,521,1004,532)            

Position<-as.fixed(Position)
Temperature<-as.fixed(Temperature)
dat<-c(Position,Temperature,observation)

model<-aov(observation~Position*Temperature)
summary(model)
##                      Df Sum Sq Mean Sq  F value   Pr(>F)    
## Position              1   7160    7160   15.998  0.00176 ** 
## Temperature           2 945342  472671 1056.117 3.25e-14 ***
## Position:Temperature  2    818     409    0.914  0.42711    
## Residuals            12   5371     448                      
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

p value interaction 0.42711 which is greater than alpha so fail to reject H0 null Hypothesis

The p-vales are as follows:

position p-value = 0.001762

Temperature p-value = 3.25e-14

position-temperature interaction p-value = 0.42711

position and temperature are significant at α=0.05

# b.Assume that both Temperature and Position are random effects
library(GAD)
Position1<-as.random(Position)
Temperature1<-as.random(Temperature)
dat2<-c(Position1,Temperature1,observation)
model1<-aov(observation~Position1*Temperature1)

gad(model1)
## Analysis of Variance Table
## 
## Response: observation
##                        Df Sum Sq Mean Sq  F value    Pr(>F)    
## Position1               1   7160    7160   17.504 0.0526583 .  
## Temperature1            2 945342  472671 1155.518 0.0008647 ***
## Position1:Temperature1  2    818     409    0.914 0.4271101    
## Residual               12   5371     448                       
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

p value interaction 0.4271101 which is greater than alpha so fail to reject H0 null Hypothesis

The p-vales are as follows:

position p-value = 0.0526583

Temperature p-value = 0.0008647

position-temperature interaction p-value = 0.4271101

position and temperature are significant at α=0.05

# c.Assume the Position effect is fixed and the Temperature effect is random.  Report p-values 
library(GAD)
Position<-as.fixed(Position)
Temperature2<-as.random(Temperature1)
dat3<-c(Position,Temperature2,observation)
model2<-aov(observation~Position*Temperature1)

gad(model2)
## Analysis of Variance Table
## 
## Response: observation
##                       Df Sum Sq Mean Sq  F value   Pr(>F)    
## Position               1   7160    7160   17.504  0.05266 .  
## Temperature1           2 945342  472671 1056.117 3.25e-14 ***
## Position:Temperature1  2    818     409    0.914  0.42711    
## Residual              12   5371     448                      
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

p value interaction 0.42711 which is greater than alpha so fail to reject H0 null Hypothesis

The p-vales are as follows:

position p-value = 0.05266

Temperature p-value = 3.25e-14

position-temperature interaction p-value = 0.42711

position and temperature are significant at α=0.05

Comments:

From the following a,b,c

Using Fixed for both Temperature and Position are significant at level of signifance the p value is 0.42711

If the Temperature and Position are random effect it shows varitions in the F and p values

if we change Position effect is fixed and the Temperature effect is random shows varitions in the F and p values

and all other values are same