#' title: "Homework 4 Cognitive task"
#' author: "Szu-Yu Chen"
#' date: "04 Oct 2020"
#載入資料
dta <- read.table("C:/Users/ASUS/Desktop/data/cognitive_task.txt", h=T)
#繪圖
VCA::varPlot(Score ~ Method/Class/ID,
Data=dta,
YLabel=list(text="Score", side=2, cex=1),
MeanLine=list(var=c("Method", "Class"),
col=c("darkred", "salmon"), lwd=c(1, 2)))
## Warning in min(x): min 中沒有無漏失的引數; 回傳 Inf
## Warning in max(x): max 中沒有無漏失的引數;回傳 -Inf

# define a ANOVA model containing Method and error term of Class (Class as Random effect)
m0 <- aov(Score ~ Method + Error(Class), data=dta)
summary(m0)
##
## Error: Class
## Df Sum Sq Mean Sq F value Pr(>F)
## Method 1 112.5 112.50 6.459 0.044 *
## Residuals 6 104.5 17.42
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## Error: Within
## Df Sum Sq Mean Sq F value Pr(>F)
## Residuals 24 18.5 0.7708
#compute a model containing Method and error terms of Method, Method*Class
m01 <- aov(Score ~ Method + Error(Method/Class), data=dta)
## Warning in aov(Score ~ Method + Error(Method/Class), data = dta): Error() model
## is singular
summary(m01)
##
## Error: Method
## Df Sum Sq Mean Sq
## Method 1 112.5 112.5
##
## Error: Method:Class
## Df Sum Sq Mean Sq F value Pr(>F)
## Residuals 6 104.5 17.42
##
## Error: Within
## Df Sum Sq Mean Sq F value Pr(>F)
## Residuals 24 18.5 0.7708
# m1 has a random intercept per Class
m1 <- lme4::lmer(Score ~ Method + (1 | Class), data=dta)
summary(m1)
## Linear mixed model fit by REML ['lmerMod']
## Formula: Score ~ Method + (1 | Class)
## Data: dta
##
## REML criterion at convergence: 101.6
##
## Scaled residuals:
## Min 1Q Median 3Q Max
## -1.3028 -0.8416 -0.0126 0.3150 2.5753
##
## Random effects:
## Groups Name Variance Std.Dev.
## Class (Intercept) 4.1615 2.040
## Residual 0.7708 0.878
## Number of obs: 32, groups: Class, 8
##
## Fixed effects:
## Estimate Std. Error t value
## (Intercept) 3.500 1.043 3.355
## MethodI2 3.750 1.475 2.542
##
## Correlation of Fixed Effects:
## (Intr)
## MethodI2 -0.707
# m11 has a random intercept per Method*Klass
m11 <- lme4::lmer(Score ~ Method + (1 | Method:Klass), data=dta)
summary(m11)
## Linear mixed model fit by REML ['lmerMod']
## Formula: Score ~ Method + (1 | Method:Klass)
## Data: dta
##
## REML criterion at convergence: 101.6
##
## Scaled residuals:
## Min 1Q Median 3Q Max
## -1.3028 -0.8416 -0.0126 0.3150 2.5753
##
## Random effects:
## Groups Name Variance Std.Dev.
## Method:Klass (Intercept) 4.1615 2.040
## Residual 0.7708 0.878
## Number of obs: 32, groups: Method:Klass, 8
##
## Fixed effects:
## Estimate Std. Error t value
## (Intercept) 3.500 1.043 3.355
## MethodI2 3.750 1.475 2.542
##
## Correlation of Fixed Effects:
## (Intr)
## MethodI2 -0.707
# confidence intervals estimated by the bootstrapping method
confint(m1, method="boot")
## Computing bootstrap confidence intervals ...
## 2.5 % 97.5 %
## .sig01 0.7983641 3.189876
## .sigma 0.6362361 1.133768
## (Intercept) 1.5120559 5.531759
## MethodI2 0.9332159 6.583586
# The end