rm(list=ls(all=TRUE)) # clear all variables graphics.off() # clear all graphics # Proactive Interference # Greg Francis # PSY 626 # 01 February 2024 # Bayesian dependent t-test # load data file PIdata<-read.csv(file="ProactiveInterference.csv",sep="\t", header=TRUE,stringsAsFactors=TRUE) # Dummy variable to indicate condition PIdata$ConditionIndex <-0* PIdata$NumCorrect PIdata$ConditionIndex[PIdata$Trial =="1"] =1 PIdata$ConditionIndex[PIdata$Trial =="5"] =2 # Full data set #---------------------- # Run traditional dependent t-test traditional <- t.test(NumCorrect ~ Trial, data=PIdata, paired=TRUE) print(traditional) #------------------------ # Bayesian models # load the rethinking library library(rethinking) # Null model: one mean for both conditions # Different baseline (intercept) for each participant PImodel0 <- map( alist( NumCorrect ~ dnorm(mu, sigma), mu <- a[Participant], a[Participant] ~ dnorm(5, 5), sigma ~ dunif(0, 7) ), data= PIdata , control=list(maxit=10000) ) cat("Finished PImodel0\n") # Alternative model 1: different mean for each condition PImodel1 <- map( alist( NumCorrect ~ dnorm(mu, sigma), mu <- a[Participant] +b[ConditionIndex], a[Participant] ~ dnorm(5, 5), b[ConditionIndex] ~ dnorm(5, 5), sigma ~ dunif(0, 7) ), data= PIdata , control=list(maxit=10000) ) cat("Finished PImodel1\n") # Compare models print(compare(PImodel0, PImodel1) )