beginningReaders: Visual lexical decision with beginning readers
In languageR: Analyzing Linguistic Data: A Practical Introduction to Statistics

Description Usage Format References Examples

Visual lexical decision latencies for beginning readers (8 year-old Dutch children).

1	data(beginningReaders)

A data frame with 7923 observations on the following 13 variables.

Word: a factor for the words.
Subject: a factor for the subjects.
LogRT: a numeric vector with the log-transformed reaction time (in ms).
Trial: a numeric vector coding the rank of the trial in the experimental list.
OrthLength: a numeric vector coding the word's length in letters.
LogFrequency: a numeric vector with log-transformed frequency in Vermeer's frequency dictionary of Dutch children's texts.
LogFamilySize: a numeric vector with the log-transformed morphological family size count (with family members judged to be unknown to young children removed).
ReadingScore: a numeric vector with a score for reading proficiency.
ProportionOfErrors: a numeric vector for the proportion of error responses for the word.
PC1: a numeric vector for the first principal component of a PCA orthogonalization of the preceding 4 reaction times
PC2: a numeric vector for the second principal component of a PCA orthogonalization of the preceding 4 reaction times
PC3: a numeric vector for the third principal component of a PCA orthogonalization of the preceding 4 reaction times
PC4: a numeric vector for the fourth principal component of a PCA orthogonalization of the preceding 4 reaction times

Perdijk, K., Schreuder, R., Verhoeven, L. and Baayen, R. H. (2006) Tracing individual differences in reading skills of young children with linear mixed-effects models. Manuscript, Radboud University Nijmegen.

## Not run: 
data(beginningReaders)
require(lme4)
require(optimx)
require(lmerTest)

beginningReaders.lmer = lmer(LogRT ~  PC1 + PC2 + PC3  + ReadingScore +
  OrthLength + I(OrthLength^2) + LogFrequency + LogFamilySize +
  (1|Word) + (1|Subject) + (0+LogFrequency|Subject) + 
  (0+OrthLength|Subject) + (0+PC1|Subject), 
  data = beginningReaders,
  control=lmerControl(optimizer="optimx",optCtrl=list(method="nlminb")))
summary(beginningReaders.lmer)

## End(Not run)