1library(plyr)
 2ddply(srchscrl, ~ Technique, function(data) summary(data$Errors))
 3ddply(srchscrl, ~ Technique, summarise, Errors.mean=mean(Errors), Errors.sd=sd(Errors))
 4
 5hist(srchscrl[srchscrl$Technique == "Search",]$Errors) # histogram
 6hist(srchscrl[srchscrl$Technique == "Scroll",]$Errors) # histogram
 7plot(Errors ~ Technique, data=srchscrl) # boxplot
 8
 9
10library(fitdistrplus)
11fit = fitdist(srchscrl[srchscrl$Technique == "Search",]$Errors, "pois", discrete=TRUE)
12gofstat(fit) # goodness-of-fit test
13fit = fitdist(srchscrl[srchscrl$Technique == "Scroll",]$Errors, "pois", discrete=TRUE)
14gofstat(fit) # goodness-of-fit test
15
16library(coin)
17wilcoxsign_test(Errors ~ Technique | Subject, data=srchscrl, distribution="exact")
18
19library(plyr)
20ddply(srchscrl, ~ Technique, function(data) summary(data$Effort))
21ddply(srchscrl, ~ Technique, summarise, Effort.mean=mean(Effort), Effort.sd=sd(Effort))
22hist(srchscrl[srchscrl$Technique == "Search",]$Effort, breaks=c(1:7), xlim=c(1,7)) # histogram
23hist(srchscrl[srchscrl$Technique == "Scroll",]$Effort, breaks=c(1:7), xlim=c(1,7)) # histogram
24plot(Effort ~ Technique, data=srchscrl, ylim=c(1,7)) # boxplot
25
26library(coin)
27wilcoxsign_test(Effort ~ Technique | Subject, data=srchscrl, distribution="exact")