Reads responses to a questionnaire from a text file
Usage
read.resp(file, na=".")
Arguments
file
File name
na
The symbol used to represent missing data
Value
A matrix, typically of zeroes and ones, representing the correct
or wrong responses given by persons (rows) to items (columns).
Details
Included for those of my students who are too faint-hearted to
write as.matrix(read.table(file, head=F)). Of course, data can
be entered into R in many other ways.
The data values in the file must be separated with blanks.
Responses are the empirical data used in IRT. Note that irtoys
deals with models for dichotomous data, and typically expects data
consisting of zeroes and ones, without any missing values
(non-responses are considered as wrong responses). In fact, there
are only two commands in irtoys that accept other kinds
of data: sco and tgp.
read.resp does accept missing data and values other than 0 and 1.
Use sco and a key to score multiple choice responses to 0/1. If
you have dichotomous data that contains NAs, you can use sco
without a key to change all NA to 0.