smdata (version 1.2)

dyslexic3: Dyslexic readers data

Description

Reading scores and nonverbal IQ scores for gender- and age-matched dyslexic and non-dyslexic readers.

Usage

data("dyslexic3")

Format

A data frame with 44 observations on the following 3 variables.

score

a numeric vector recording childrens' scores on a reading accuracy test

dys

a numeric vector taking the value 1 if dyslexic and 0 if not

ziq

a numeric vector recording childrens' nonverbal IQ scores, standardized to have a mean of 0 and standard deviation of 1

Details

The reading accuracy scores have a maximum score of 1, indicating a perfect score on the test. In the Example 6.2 analysis, these are recoded to .99; whereas in the 1's inflated model in Ch. 6 and the censored regression model in Ch. 7 they have a value of 1.

References

Pammer, K., & Kevan, A. (2007). The contribution of visual sensitivity, phonological processing, and nonverbal IQ to childrens reading. Scientific Studies in Reading, 11, 33-53.

Smithson, M. J., & Verkuilen, J. (2006). A better lemon squeezer? maximum likelihood regression with beta-distributed dependent variables. Psychological Methods, 11, 54-71.

Examples

# NOT RUN {
data("dyslexic3", package="smdata")
# }